Mechanisms of Context Conditioning in the Developing Rat.
Abstract The article reviews our studies of contextual fear conditioning (CFC) in rats during a period of development---Postnatal Day (PND) 17-33---that represents the late-infant, juvenile, and early-adolescent stages. These studies seek to acquire 'systems level' knowledge of brain and memory development and apply it to a rodent model of Fetal Alcohol Spectrum Disorder (FASD). This rodent model focuses on alcohol exposure from PND4-9, a period of brain development equivalent to the human third trimester, when neocortex, hippocampus, and cerebellum are especially vulnerable to adverse effects of alcohol. Our rese...
Source: Neurobiology of Learning and Memory - January 19, 2021 Category: Neurology Authors: Stanton ME, Murawski NJ, Jablonski SA, Robinson-Drummer PA, Heroux NA Tags: Neurobiol Learn Mem Source Type: research

A predictive account of how novelty influences declarative memory.
Abstract A rich body of studies in the human and non-human literature has examined the question how novelty influences memory. For a variety of different stimuli, ranging from simple objects and words to vastly complex scenarios, the literature reports that novelty improves memory in some cases, but impairs memory in other cases. In recent attempts to reconcile these conflicting findings, novelty has been divided into different subtypes, such as relative versus absolute novelty, or stimulus versus contextual novelty. Nevertheless, a single overarching theory of novelty and memory has been difficult to attain, prob...
Source: Neurobiology of Learning and Memory - January 18, 2021 Category: Neurology Authors: Alexander Quent J, Henson RN, Greve A Tags: Neurobiol Learn Mem Source Type: research

Stress-induced resistance to fear memory destabilization is associated with an impairment of Lys-48-linked protein polyubiquitination in the Basolateral Amygdala: influence of D-cycloserine.
In conclusion, the protein polyubiquitination-dependent destabilization is impaired after the recall of stress-induced resistant memories, with D-cycloserine restoring such molecular event. Hence, the present report contributes to furthercharacterize the neurobiological events associated with stress-induced memory resistance as well as to corroborate the connection between glutamatergic signaling,protein degradation and memory destabilization in stress-induced resistant memories. PMID: 33476748 [PubMed - as supplied by publisher] (Source: Neurobiology of Learning and Memory)
Source: Neurobiology of Learning and Memory - January 18, 2021 Category: Neurology Authors: Javier Espejo P, Ortiz V, Delia Martijena I, Alejandro Molina V Tags: Neurobiol Learn Mem Source Type: research

Brd4 participates in epigenetic regulation of the extinction of remote auditory fear memory.
Abstract BACKGROUND: Inaccurate fear memories can be maladaptive and potentially portrait a core symptomatic dimension of fear adaptive disorders such as post-traumatic stress disorder (PTSD), which is generally characterized by an intense and enduring memory for the traumatic events. Evidence exists in support of epigenetic regulation of fear behavior. Brd4, a member of the bromodomain and extra-terminal domain (BET) protein family, serves as a chromatin "reader" by binding to histones in acetylated lysine residues, and hence promotes transcriptional activities. However, less is known whether Brd4 parti...
Source: Neurobiology of Learning and Memory - January 15, 2021 Category: Neurology Authors: Huang FL, Li F, Zhang WJ, Li SJ, Yang ZH, Yang TL, Qi J, Duan Q, Li CQ Tags: Neurobiol Learn Mem Source Type: research

The role of p21-activated kinase in maintaining the fear learning-induced modulation of excitation/inhibition ratio in lateral amygdala.
Abstract We study the relations between different learning paradigms and enduring changes in excitatory synaptic transmission. We here show that auditory fear conditioning (AFC), but not olfactory fear conditioning (OFC) training, led to enduring enhancement in AMPA-mediated miniature EPSCs (mEPSCs). Moreover, olfactory unpaired training led to a stable significant reduction in excitatory synaptic transmission. However, olfactory discrimination learning (OD) did not modulate postsynaptic AMPA-mediated mEPSCs in LA. The p21-activated kinase (PAK) activity, previously shown to have a key role in maintaining persiste...
Source: Neurobiology of Learning and Memory - January 15, 2021 Category: Neurology Authors: Paul BK, Barkai E, Lamprecht R Tags: Neurobiol Learn Mem Source Type: research

Consolidation and generalisation across sleep depend on individual EEG factors and sleep spindle density.
Abstract Sleep is involved in both the consolidation of discrete episodes, as well as the generalisation of acquired memories into schemata. Here, we have isolated early versus late periods of sleep in order to replicate previous behavioural findings and to demonstrate: i) that distinct sleep and sleep electroencephalography (EEG) factors influence the generalisation of learned information, and; ii) that the consolidation and generalisation of memory across sleep depends on individual alpha frequency (IAF) and strength of initial encoding. Subjects underwent a night-half protocol with polysomnography (PSG), and co...
Source: Neurobiology of Learning and Memory - January 15, 2021 Category: Neurology Authors: Chatburn A, Lushington K, Kohler MJ Tags: Neurobiol Learn Mem Source Type: research

Consequence of stroke for feature recall and binding in visual working me.
Abstract Visual memory for objects involves the integration, or binding, of individual features into a coherent representation. We used a novel approach to assess feature binding, using a delayed-reproduction task in combination with computational modeling and lesion analysis. We assessed stroke patients and neurotypical controls on a visual working memory task in which spatial arrays of colored disks were presented. After a brief delay, participants either had to report the color of one disk cued by its location or the location of one disk cued by its color. Our results demonstrate that, in the controls, report i...
Source: Neurobiology of Learning and Memory - January 15, 2021 Category: Neurology Authors: Lugtmeijer S, Schneegans S, Lammers NA, Geerligs L, Erik de Leeuw F, H F de Haan E, Bays PM, P C Kessels R Tags: Neurobiol Learn Mem Source Type: research

Dorsomedial Striatal Contributions to Different Forms of Risk/Reward Decision Making.
Abstract Optimal decision making involving reward uncertainty is integral to adaptive goal-directed behavior. In some instances, these decisions are guided by internal representations of reward history, whereas in other situations, external cues inform a decision maker about how likely certain actions may yield reward. Different regions of the frontal lobe form distributed networks with striatal and amygdalar regions that facilitate different types of risk/reward decision making. The dorsal medial striatum (DMS) is one key output region of the prefrontal cortex, yet there have been few preclinical studies investig...
Source: Neurobiology of Learning and Memory - December 28, 2020 Category: Neurology Authors: Schumacher JD, van Holstein M, Bagrodia V, Le Bouder HB, Floresco SB Tags: Neurobiol Learn Mem Source Type: research

Systemic HDAC3 inhibition ameliorates impairments in synaptic plasticity caused by simulated galactic cosmic radiation exposure in male mice.
od MA Abstract Deep space travel presents a number of measurable risks including exposure to a spectrum of radiations of varying qualities, termed galactic cosmic radiation (GCR) that are capable of penetrating the spacecraft, traversing through the body and impacting brain function. Using rodents, studies have reported that exposure to simulated GCR leads to cognitive impairments associated with changes in hippocampus function that can persist as long as one-year post exposure with no sign of recovery. Whether memory can be updated to incorporate new information in mice exposed to GCR is unknown. Further, mechani...
Source: Neurobiology of Learning and Memory - December 23, 2020 Category: Neurology Authors: Keiser AA, Kramár EA, Dong T, Shanur S, Pirodan M, Ru N, Acharya MM, Baulch JE, Limoli CL, Wood MA Tags: Neurobiol Learn Mem Source Type: research

Acute exercise following skill practice promotes motor memory consolidation in parkinson's disease.
ib S Abstract Acute cardiovascular exercise has shown to promote neuroplastic processes supporting the consolidation of newly acquired motor skills in healthy adults. First results suggest that this concept may be transferred to populations with motor and cognitive dysfunctions. In this context, Parkinson's disease (PD) is highly relevant since patients demonstrate deficits in motor learning. Hence, in the present study we sought to explore the effect of a single post-practice exercise bout on motor memory consolidation in PD. For this purpose, 17 patients with PD (Hoehn and Yahr: 1 - 2.5, age: 60.1 ± 7.9 y...
Source: Neurobiology of Learning and Memory - December 20, 2020 Category: Neurology Authors: Wanner P, Winterholler M, Gaßner H, Winkler J, Klucken J, Pfeifer K, Steib S Tags: Neurobiol Learn Mem Source Type: research

Improving consolidation by applying anodal transcranial direct current stimulation at primary motor cortex during repetitive practice.
Abstract Engagement of primary motor cortex (M1) is important for successful consolidation of motor skills. Recruitment of M1 has been reported to be more extensive during interleaved compared to repetitive practice and this differential recruitment has been proposed to contribute to the long-term retention benefit associated with interleaved practice. The present study administered anodal direct current stimulation (tDCS) during repetitive practice in an attempt to increase M1 activity throughout repetitive practice with the goal to improve the retention performance of individuals exposed to this training format....
Source: Neurobiology of Learning and Memory - December 18, 2020 Category: Neurology Authors: Kim T, Kim H, Wright DL Tags: Neurobiol Learn Mem Source Type: research

Sustained and transient gray matter volume changes after n-back training: a VBM study.
Marin-Marin L, Aguirre N, Ávila C Abstract Working memory training causes functional adaptations in the brain, which include changes in activation and functional connectivity that remain stable over time. Few studies have investigated gray matter (GM) changes after working memory training, and they have produced heterogeneous results without clarifying the stable effects of training. The present study was designed to test for sustained and transient anatomic changes after only 200 minutes of working memory training. The voxel-based morphometry technique was used in order to investigate the GM changes produ...
Source: Neurobiology of Learning and Memory - December 18, 2020 Category: Neurology Authors: Miró-Padilla A, Bueichekú E, Adrián-Ventura J, Costumero V, Palomar-García MÁ, Villar-Rodríguez E, Marin-Marin L, Aguirre N, Ávila C Tags: Neurobiol Learn Mem Source Type: research

Age- and Sex-Specific Fear Conditioning Deficits in Mice Lacking Pcdh10, an Autism Associated Gene.
Abstract PCDH10 is a gene associated with Autism Spectrum Disorder. It is involved in the growth of thalamocortical projections and dendritic spine elimination. Previously, we characterized Pcdh10 haploinsufficient mice (Pcdh10+/- mice) and found male-specific social deficits and dark phase hypoactivity. Pcdh10+/- males exhibit increased dendritic spine density of immature morphology, decreased NMDAR expression, and decreased gamma synchronization in the basolateral amygdala (BLA). Here, we further characterize Pcdh10+/- mice by testing for fear memory, which relies upon BLA function. We used both male and female ...
Source: Neurobiology of Learning and Memory - December 16, 2020 Category: Neurology Authors: Ferri SL, Dow HC, Schoch H, Youn Lee J, Brodkin ES, Abel T Tags: Neurobiol Learn Mem Source Type: research

Ketamine anesthesia enhances fear memory consolidation via noradrenergic activation in the basolateral amygdala.
Abstract Trauma patients treated with ketamine during emergency care present aggravated early post- traumatic stress reaction which is highly predictive of post-traumatic stress disorder (PTSD) development and severity. The use of ketamine in the acute trauma phase may directly or indirectly interfere with neural processes of memory consolidation of the traumatic event, thus leading to the formation of maladaptive memories, a hallmark symptom of PTSD. We have recently shown that ketamine anesthesia, immediately after a traumatic event, enhances memory consolidation and leads to long-lasting alterations of social b...
Source: Neurobiology of Learning and Memory - December 14, 2020 Category: Neurology Authors: Morena M, Colucci P, Mancini GF, De Castro V, Peloso A, Schelling G, Campolongo P Tags: Neurobiol Learn Mem Source Type: research

Effects of Aversive Conditioning on Expression of Physiological Stress in Honey Bees (Apis mellifera).
Abstract Stress is defined as any deviation from an organism's baseline physiological levels. Therefore, introduction of new stimuli and information, such as in learning, can be defined as a stressor. A large body of research exists examining the role that stress plays in learning, but virtually none addresses whether or not learning itself is a measurable cause of stress. The current study used a wide variety of learning centric stress responses. Researchers examined changes in expression of ten stress and learning related genes in various physiological systems in domesticated honey bees (Apis mellifera) as a res...
Source: Neurobiology of Learning and Memory - December 14, 2020 Category: Neurology Authors: Black TE, Fofah O, Dinges CW, Ortiz-Alvarado CA, Avalos A, Ortiz-Alvarado Y, Abramson CI Tags: Neurobiol Learn Mem Source Type: research

Ontogeny of Spontaneous Recognition Memory in Rodents.
Abstract Spontaneous recognition memory tasks explore thewhat,whereandwhencomponents of recognition memory. These tasks are widely used in rodents to assess cognitive function across the lifespan. While several neurodevelopmental and mental disorders present symptom onset in early life, very little is known about how memories are expressed in early life, and as a consequence how they may be affected in pathological conditions. In this review, we conduct an analysis of the studies examining the expression of spontaneous recognition memory in young rodents. We compiled studies using four different tasks: novel objec...
Source: Neurobiology of Learning and Memory - December 8, 2020 Category: Neurology Authors: Cruz-Sanchez A, Wilkin J, Arruda-Carvalho M Tags: Neurobiol Learn Mem Source Type: research

Critical Role of Hippocampal Muscarinic Acetylcholine Receptors on Memory Reconsolidation in mice.
Abstract Over the years, experimental and clinical evidence has given support to the idea that acetylcholine (Ach) plays an essential role in mnemonic phenomena. On the other hand, the Hippocampus is already known to have a key role in learning and memory. What is yet unclear is how the Ach receptors may contribute to this brain region role during memory retrieval. The Ach receptors are divided into two broad subtypes: the ionotropic nicotinic acetylcholine receptors and the metabotropicmuscarinicacetylcholinereceptors. Back in 2010, we demonstrated for the first time the critical role of hippocampal α7 nico...
Source: Neurobiology of Learning and Memory - December 8, 2020 Category: Neurology Authors: Krawczyk MC, Millan J, Blake MG, Boccia MM Tags: Neurobiol Learn Mem Source Type: research

Integrity of the Uncinate Fasciculus is Associated with Emotional Pattern Separation-Related fMRI Signals in the Hippocampal Dentate and CA3.
sa MA Abstract Alterations in white matter integrity have been demonstrated in a number of psychiatric disorders involving emotional disruptions. One such pathway - the uncinate fasciculus - connects the orbitofrontal cortex (OFC) to the medial temporal lobes (MTL) and has been associated with early life adversity, maltreatment, anxiety, and depression. While it is purported to play a role in episodic memory and discrimination, its exact function remains poorly understood. We have previously described the role of the amygdala and dentate (DG)/CA3 fields of the hippocampus in the mnemonic discrimination of emotiona...
Source: Neurobiology of Learning and Memory - December 4, 2020 Category: Neurology Authors: Granger SJ, Leal SL, Saraí Larson M, Janecek JT, McMillan L, Stern H, Yassa MA Tags: Neurobiol Learn Mem Source Type: research

Title: Disruption of rat deep cerebellar perineuronal net alters eyeblink conditioning and neuronal electrophysiology.
Abstract The perineuronal net (PNN) is a specialized type of extracellular matrix found in the central nervous system. The PNN forms on fast spiking neurons during postnatal development but the ontogeny of PNN development has yet to be elucidated. By studying the development and prevalence of the PNN in the juvenile and adult rat brain, we may be able to understand the PNN's role in development and learning and memory. We show that the PNN is fully developed in the deep cerebellar nuclei (DCN) of rats by P18. By using enzymatic digestion of the PNN with chondroitinase ABC (ChABC), we are able to study how digestio...
Source: Neurobiology of Learning and Memory - December 4, 2020 Category: Neurology Authors: O'Dell DE, Schreurs BG, Smith-Bell C, Wang D Tags: Neurobiol Learn Mem Source Type: research

Timing Matters: Transcranial Direct Current Stimulation After Extinction Learning Impairs Subsequent Fear Extinction Retention.
Conclusions Participants in the tDCS group showed impaired fear extinction retention on day 2, marked by significant generalisation of fear to the safety stimulus. This contrasts with earlier studies showing improved extinction retention when stimulation occurred during encoding of extinction learning, compared to immediate consolidation as in our study. These findings may have important implications for the use of tDCS during exposure therapy for anxiety and trauma disorders. PMID: 33278591 [PubMed - as supplied by publisher] (Source: Neurobiology of Learning and Memory)
Source: Neurobiology of Learning and Memory - December 2, 2020 Category: Neurology Authors: Ney LJ, Vicario CM, Nitsche MA, Felmingham KL Tags: Neurobiol Learn Mem Source Type: research

Pharmacological inhibition of Phosphodiesterase 7 enhances consolidation processes of spatial memory.
s M Abstract Augmentation of cAMP signaling through inhibition of phosphodiesterases (PDE) is known to enhance plasticity and memory. Inhibition of PDE4 enhances consolidation into memory, but less is known about the role of other cAMP specific PDEs. Here, we tested the effects of oral treatment with a selective inhibitor of PDE7 of nanomolar potency on spatial and contextual memory. In an object location task, doses of 0.3-3 mg/kg administered 3 hours after training dose-dependently attenuated time-dependent forgetting in rats. Significant enhancement of memory occurred at a dose of 3 mg/kg with corresponding bra...
Source: Neurobiology of Learning and Memory - December 2, 2020 Category: Neurology Authors: McQuown S, Paes D, Baumgärtel K, Prickaerts J, Peters M Tags: Neurobiol Learn Mem Source Type: research

Chemogenetic silencing of hippocampus and amygdala reveals a double dissociation in periadolescent obesogenic diet-induced memory alterations.
Abstract In addition to numerous metabolic comorbidities, obesity is associated with several adverse neurobiological outcomes, especially learning and memory alterations. Obesity prevalence is rising dramatically in youth and is persisting in adulthood. This is especially worrying since adolescence is a crucial period for the maturation of certain brain regions playing a central role in memory processes such as the hippocampus and the amygdala. We previously showed that periadolescent, but not adult, exposure to obesogenic high-fat diet (HFD) had opposite effects on hippocampus- and amygdala-dependent memory, impa...
Source: Neurobiology of Learning and Memory - December 1, 2020 Category: Neurology Authors: Naneix F, Bakoyiannis I, Santoyo-Zedillo M, Bosch-Bouju C, Pacheco-Lopez G, Coutureau E, Ferreira G, OBETEEN Consortium Tags: Neurobiol Learn Mem Source Type: research

Frontal Cortex Stroke-induced Impairment in Spatial Working Memory on the Trial-unique Nonmatching-to-location Task in Mice.
Abstract Stroke-induced cognitive impairments are of significant concern, however mechanisms that underpin these impairments remain poorly understood and researched. To further characterise cognitive impairments in our frontal cortex stroke model, and to align our assessments with what is used clinically, we tested young C57BL/6J mice trained in operant touchscreen chambers to complete the trial-unique nonmatched-to-location (TUNL) task. Based on baseline performance, animals were given either stroke (n=12) or sham (n=12) surgery using a photothrombosis model, bilaterally targeting the frontal cortex. Upon recover...
Source: Neurobiology of Learning and Memory - December 1, 2020 Category: Neurology Authors: Houlton J, Barwick D, Clarkson AN Tags: Neurobiol Learn Mem Source Type: research

Neurobiological changes in striatal glutamate are associated with trait impulsivity of differential reinforcement of low-rate-response behavior in male rats.
Abstract Impulsive action can be measured using rat's responses on a differential reinforcement of low-rate-response (DRL) task in which performance may be varied between rats. Nevertheless, neurobiological profiles underlying the trait impulsivity of DRL behavior remain largely unknown. Here, in vivo non-invasive proton magnetic resonance spectroscopy (1H-MRS) and Western blot assay were performed to assess neurobiological changes in the dorsal striatum (DS) and nucleus accumbens (NAc) in relation to individual differences in DRL behavior. A cohort of rats was subjected to acquire a DRL task over 14 daily session...
Source: Neurobiology of Learning and Memory - November 27, 2020 Category: Neurology Authors: Chuang CY, Tsai SY, Chen SF, Yang YH, Chao CC, Yen NS, Liao RM Tags: Neurobiol Learn Mem Source Type: research

The association between sleep-wake ratio and overnight picture recognition is moderated by BDNF genotype.
We examined how the natural distribution of wake and sleep between encoding and retrieval associated with overnight picture recognition accuracy among 161 adolescents following their typical sleep schedule with an in-home polysomnography. The memorized pictures varied in their level of arousal (calm to exciting) and valence (negative to positive). Suspecting genotypic influence on the sensitivity for sleep/wake dynamics, we also assessed if these associations were affected by known gene polymorphisms involved in neural plasticity and sleep homeostasis: brain-derived neurotrophic factor (BDNF) Val66Met and Catechol-O-methyl...
Source: Neurobiology of Learning and Memory - November 27, 2020 Category: Neurology Authors: Halonen R, Kuula L, Lahti J, Räikkönen K, Pesonen AK Tags: Neurobiol Learn Mem Source Type: research

Selective activation of the right hippocampus during navigation by spatial cues in domestic chicks (Gallus gallus).
Abstract In different vertebrate species, hippocampus plays a crucial role for spatial orientation. However, even though cognitive lateralization is widespread in the animal kingdom, the lateralization of this hippocampal function has been poorly studied. The aim of the present study was to investigate the lateralization of hippocampal activation in domestic chicks, during spatial navigation in relation to free-standing objects. Two groups of chicks were trained to find food in one of the feeders located in a large circular arena. Chicks of one group solved the task using the relational spatial information provide...
Source: Neurobiology of Learning and Memory - November 23, 2020 Category: Neurology Authors: Morandi-Raikova A, Mayer U Tags: Neurobiol Learn Mem Source Type: research

Nucleus reuniens of the thalamus controls fear memory reconsolidation.
Abstract The nucleus reuniens has been shown to support the acquisition, consolidation, maintenance, destabilization upon retrieval, and extinction of aversive memories. However, the direct participation of this thalamic subregion in memory reconsolidation is yet to be examined. The present study addressed this question in contextually fear-conditioned rats. Post-reactivation infusion of the GABAA receptor agonist muscimol, the glutamate N2A-containing NMDA receptor antagonist TCN-201, or the protein synthesis inhibitor anisomycin into the NR induced significant impairments in memory reconsolidation. Administering...
Source: Neurobiology of Learning and Memory - November 23, 2020 Category: Neurology Authors: Troyner F, Jose Bertoglio L Tags: Neurobiol Learn Mem Source Type: research

Age-related alterations of default mode network in autobiographical memory: Recent versus remote events.
Abstract Previous studies have shown that the vividness of autobiographical memory decreases over time, and older adults often retrieve fewer details than young adults. However, the age-by-temporal distance (i.e., recent versus remote events) effect on autobiographical memory and underlying neural mechanisms are less understood. We recruited 25 young adults and 27 older adults to perform an fMRI-adapted autobiographical memory task with different temporal distances. The results showed that older adults' vividness ratings were generally higher than that of young adults, but were less sensitive to temporal distances...
Source: Neurobiology of Learning and Memory - November 20, 2020 Category: Neurology Authors: Xu HZ, Xu XX, Lei X, Yu J Tags: Neurobiol Learn Mem Source Type: research

Psychostimulants may block long-term memory formation via degraded sleep in healthy adults.
Abstract Sleep is vital for biological function and long-term memory formation, with preferential enhancement of emotionally laden content. A growing trend in healthy young adults is the non-medical use of psychostimulants, or "smart drugs", to prevent sleep and, hopefully, enhance cognition. However, the effect of these drugs on sleep-dependent memory processes are unclear. Here, in a within-subject, double-blind, placebo-controlled design, we investigated the impact of morning administration of dextroamphetamine on memory retention of negative and neutral pictures after 1) 12 hours of wake, and 2) 24 h...
Source: Neurobiology of Learning and Memory - November 20, 2020 Category: Neurology Authors: Whitehurst LN, Mednick SC Tags: Neurobiol Learn Mem Source Type: research

Corrigendum to "Hippocampal HECT E3 ligase inhibition facilitates consolidation, retrieval, and reconsolidation, and inhibits extinction of contextual fear memory". [Neurobiol. Learn. Memory 167 (2020) 107-135].
Corrigendum to "Hippocampal HECT E3 ligase inhibition facilitates consolidation, retrieval, and reconsolidation, and inhibits extinction of contextual fear memory". [Neurobiol. Learn. Memory 167 (2020) 107-135]. Neurobiol Learn Mem. 2020 Nov 12;:107329 Authors: Redondo J, Popik B, Casagrande M, Silva MO, Quillfeldt JA, Alvares LO, Mello E Souza T PMID: 33189507 [PubMed - as supplied by publisher] (Source: Neurobiology of Learning and Memory)
Source: Neurobiology of Learning and Memory - November 12, 2020 Category: Neurology Authors: Redondo J, Popik B, Casagrande M, Silva MO, Quillfeldt JA, Alvares LO, Mello E Souza T Tags: Neurobiol Learn Mem Source Type: research

Motor learning rapidly increases synaptogenesis and astrocytic structural plasticity in the rat cerebellum.
Abstract Motor-skill learning is associated with cerebellar synaptogenesis and astrocytic hypertrophy, but most of these assessments of cerebellar ultrastructure have been completed after one month of training. After one month of training, the motor-skills necessary to complete these tasks have been acquired for weeks. This experiment aimed to characterize cerebellar ultrastructure during the acquisition phase of motor-skill learning, at a point when motor performance is still improving. Male and female rats trained for four days on the acrobatic motor learning task, which involved traversing challenging obstacles...
Source: Neurobiology of Learning and Memory - November 10, 2020 Category: Neurology Authors: Stevenson ME, Nazario AS, Czyz AM, Owen HA, Swain RA Tags: Neurobiol Learn Mem Source Type: research

Increased Dynamic Flexibility in the Medial Temporal Lobe Network Following an Exercise Intervention Mediates Generalization of Prior Learning.
Abstract Recent work has conceptualized the brain as a network comprised of groups of sub-networks or modules. "Flexibility" of brain network(s) indexes the dynamic reconfiguration of comprising modules. Using novel techniques from dynamic network neuroscience applied to high-resolution resting-state functional magnetic resonance imaging (fMRI), the present study investigated the effects of an aerobic exercise intervention on the dynamic rearrangement of modular community structure-the measure of neural flexibility-within the medial temporal lobe (MTL) network. The MTL is one of the earliest brain region...
Source: Neurobiology of Learning and Memory - November 10, 2020 Category: Neurology Authors: Sinha N, Berg CN, Yassa MA, Gluck MA Tags: Neurobiol Learn Mem Source Type: research

Why is synaptic plasticity not enough?
PMID: 33137462 [PubMed - as supplied by publisher] (Source: Neurobiology of Learning and Memory)
Source: Neurobiology of Learning and Memory - October 30, 2020 Category: Neurology Authors: Hansel C, Disterhoft JF Tags: Neurobiol Learn Mem Source Type: research

Acute exercise enhances fear extinction through a mechanism involving central mTOR signaling.
Abstract Impaired fear extinction, combined with the likelihood of fear relapse after exposure therapy, contributes to the persistence of many trauma-related disorders such as anxiety and post-traumatic stress disorder. Identifying mechanisms to aid fear extinction and reduce relapse could provide novel strategies for augmentation of exposure therapy. Exercise can enhance learning and memory and augment fear extinction of traumatic memories in humans and rodents. One factor that could contribute to enhanced fear extinction following exercise is the mammalian target of rapamycin (mTOR). mTOR is a translation regula...
Source: Neurobiology of Learning and Memory - October 16, 2020 Category: Neurology Authors: Moya NA, Tanner MK, Smith AM, Balolia A, K P Davis J, Bonar K, Jaime J, Hubert T, Silva J, Whitworth W, Loetz EC, Bland ST, Greenwood BN Tags: Neurobiol Learn Mem Source Type: research

Guanfacine's Mechanism of Action in Treating Prefrontal Cortical Disorders: Successful Translation Across Species.
Abstract The selective norepinephrine (NE) α2A-adrenoceptor (α2A-AR) agonist, guanfacine (Intuniv™), is FDA-approved for treating Attention Deficit Hyperactivity Disorder (ADHD) based on research in animals, a translational success story. Guanfacine is also widely used off-label in additional mental disorders that involve impaired functioning of the prefrontal cortex (PFC), including stress-related disorders such as substance abuse, schizotypic cognitive deficits, and traumatic brain injury. The PFC subserves high order cognitive and executive functions including working memory, abstract reasonin...
Source: Neurobiology of Learning and Memory - October 16, 2020 Category: Neurology Authors: Arnsten AFT Tags: Neurobiol Learn Mem Source Type: research

A brief period of sleep deprivation negatively impacts the acquisition, consolidation, and retrieval of object-location memories.
Abstract Memory is a cognitive concept and refers to the storage of information over a longer time period. It exists of a series of complementary processes; acquisition, consolidation, and retrieval. Each of these processes has its own partly unique neurobiological signature. Sleep deprivation is known to impair hippocampus-dependent long-term memories. Many studies have used extended periods of wakefulness, affecting all three memory processes, thereby making it unable to determine how each of the processes is affected by sleep loss, separately. Others have extensively examined the effects on memory consolidation...
Source: Neurobiology of Learning and Memory - October 12, 2020 Category: Neurology Authors: Heckman PRA, Roig Kuhn F, Meerlo P, Havekes R Tags: Neurobiol Learn Mem Source Type: research

Cross-modal involvement of the primary somatosensory cortex in visual working memory: A repetitive TMS study.
Abstract Recent literature suggests that the primary somatosensory cortex (S1), once thought to be a low-level area only modality-specific, is also involved in higher-level, cross-modal, cognitive functions. In particular, electrophysiological studies have highlighted that the cross-modal activation of this area may also extend to visual Working Memory (WM), being part of a mnemonic network specific for the temporary storage and manipulation of visual information concerning bodies and body-related actions. However, the causal recruitment of S1 in the WM network remains speculation. In the present study, by taking ...
Source: Neurobiology of Learning and Memory - October 12, 2020 Category: Neurology Authors: Guidali G, Roncoroni C, Papagno C, Bolognini N Tags: Neurobiol Learn Mem Source Type: research

Midbrain circuits of novelty processing.
Abstract Novelty triggers an increase in orienting behavior that is critical to evaluate the potential salience of unknown events. As novelty becomes familiar upon repeated encounters, this increase in response rapidly habituates as a form of behavioral adaptation underlying goal-directed behaviors. Many neurodevelopmental, psychiatric and neurodegenerative disorders are associated with abnormal responses to novelty and/or familiarity, although the neuronal circuits and cellular/molecular mechanisms underlying these natural behaviors in the healthy brain are largely unknown, as is the maladaptive processes that oc...
Source: Neurobiology of Learning and Memory - October 11, 2020 Category: Neurology Authors: Tapper AR, Molas S Tags: Neurobiol Learn Mem Source Type: research

Disconnection of the perirhinal and insular cortices severely disrupts taste neophobia.
DISCONNECTION OF THE PERIRHINAL AND INSULAR CORTICES SEVERELY DISRUPTS TASTE NEOPHOBIA. Neurobiol Learn Mem. 2020 Oct 08;:107324 Authors: Ramos JMJ Abstract It is well known that the perirhinal (Prh) and insular (IC) cortices are reciprocally connected, mainly through ipsilateral projections. Although some studies have demonstrated that excitotoxic lesions to these regions, each separately, disrupt taste neophobia, it is not yet known whether the two regions have functional interactions with one another. To find out if they form a functional unit, we examined the effects of crossed excitotoxic lesions...
Source: Neurobiology of Learning and Memory - October 8, 2020 Category: Neurology Authors: Ramos JMJ Tags: Neurobiol Learn Mem Source Type: research

The role of dopamine D1 receptors in MDMA-induced memory impairments.
Abstract (±) 3,4-methylenedioxymethamphetamine (MDMA) is a recreationally abused psychostimulant that impairs memory performance. This effect is often attributed to a working memory impairment resulting from compromised serotonin systems. However, recent evidence from non-human animal experimental studies suggests that acute MDMA may indirectly impair memory performance through overstimulation of dopamine (DA) D1 receptors, which increases perseverative responding during memory tasks. This hypothesis was explored using DA D1 mutant (DAD1-/-) rats which possess a selective down-regulation in functional D1 re...
Source: Neurobiology of Learning and Memory - October 5, 2020 Category: Neurology Authors: Squire H, Youn J, Ellenbroek BA, Harper DN Tags: Neurobiol Learn Mem Source Type: research

Early-life stress is associated with a preponderance of habitual responding in a novel instrumental avoidance learning paradigm.
Abstract There is substantial evidence linking early-life stress (ELS) to negative health outcomes in adulthood, including addiction. However, the neurocognitive and behavioral mechanisms through which ELS increases these risks remain unclear. To address this gap in knowledge, we developed a novel instrumental learning paradigm to explore the effects of ELS on the balance of habitual versus goal-directed learning. Habits efficiently reproduce repetitive behaviors but are inflexible whenreward contingencies related to those behaviors change. Persisting in performing a response after its outcome has been devalued is...
Source: Neurobiology of Learning and Memory - September 30, 2020 Category: Neurology Authors: Gordon AL, Patterson TK, Knowlton BJ Tags: Neurobiol Learn Mem Source Type: research

Neural synchronization between the anterior cingulate and orbitofrontal cortices during effort-based decision making.
Abstract Optimal decision making reflects the ability to choose the most advantageous option for various alternatives so that the anterior cingulate cortex is an important area involved in effort-based decision making. The current study aimed to investigate the functional connectivity between the ACC (anterior cingulate cortex) and the orbitofrontal cortex (OFC) during effort-based decision-making. A T-maze decision-making task with different rewards (large vs. small reward) and costs (high vs. low effort) was used, and simultaneously, local field potentials (LFP) from the ACC and OFC were also recorded in male Wi...
Source: Neurobiology of Learning and Memory - September 29, 2020 Category: Neurology Authors: Fatahi Z, Ghorbani A, Ismail Zibaii M, Haghparast A Tags: Neurobiol Learn Mem Source Type: research

Using internal memory representations in associative learning to study hallucination-like phenomenon.
Abstract Studies of Pavlovian conditioning have enriched our understanding of how relations among events can adaptively guide behavior through the formation and use of internal mental representations. In this review, we illustrate how internal representations flexibly integrate new updated information in reinforcer revaluation to influence relationships to impact actions and outcomes. We highlight representation-mediated learning to show the similarities in properties and functions between internally generated and directly activated representations, and how normal perception of internal representations could contr...
Source: Neurobiology of Learning and Memory - September 29, 2020 Category: Neurology Authors: Teng Koh M, Gallagher M Tags: Neurobiol Learn Mem Source Type: research

Generalization and the hippocampus: More than one story?
Abstract Memory-based cognition depends on both the ability to remember specific details of individual experiences and the ability to combine information across experiences to generalize and derive new knowledge. A hippocampal role in rapid encoding of specific events is long established. More recent research also demonstrates hippocampal contributions to generalization, but their nature is still debated. The current review provides an overview of hippocampal-based generalization in two lines of research-episodic inference and categorization-and discusses evidence for four candidate mechanisms and representational...
Source: Neurobiology of Learning and Memory - September 28, 2020 Category: Neurology Authors: Zeithamova D, Bowman CR Tags: Neurobiol Learn Mem Source Type: research

Repeated Mild Traumatic Brain Injuries Impair Visual Discrimination Learning in Adolescent Mice.
Abstract Cognitive deficits following a mild traumatic brain injury (mTBI) are common and are associated with learning deficits in school-age children. Some of these deficits include problems with long-term memory, working memory, processing speeds, attention, mental fatigue, and executive function. Processing speed deficits have been associated with alterations in white matter, but the underlying mechanisms of many of the other deficits are unclear. Without a clear understanding of the underlying mechanisms we cannot effectively treat these injuries. The goal of these studies is to validate a translatable touchsc...
Source: Neurobiology of Learning and Memory - September 23, 2020 Category: Neurology Authors: Pinkowski NJ, Guerin J, Zhang H, Carpentier ST, McCurdy KE, Pacheco JM, Mehos CJ, Brigman JL, Morton RA Tags: Neurobiol Learn Mem Source Type: research

Human-induced pluripotent stem cells as a model for studying sporadic Alzheimer's disease.
Abstract The discovery of induced pluripotent stem cell (iPSC) technology has the potential to accelerate scientific research for Alzheimer's disease (AD). iPSCs are therefore increasingly considered for AD modeling and drug development. Nevertheless, most of the work conducted so far has mainly focused on iPSC models from patients with familial AD (fAD), while actually sporadic AD (sAD) is more prevalent and represents over 90% of the AD cases in the population. The development of more sAD models is therefore key for studying this multifactorial disorder. In fact, probing the unique genomes of sAD patients and th...
Source: Neurobiology of Learning and Memory - September 21, 2020 Category: Neurology Authors: Riemens RJM, Kenis G, van den Beucken T Tags: Neurobiol Learn Mem Source Type: research

Persistent Changes in Extracellular Lactate Dynamics Following Synaptic Potentiation.
Abstract A diverse array of neurometabolic coupling mechanisms exist within the brain to ensure that sufficient metabolite availability is present to meet both acute and chronic energetic demands. Excitatory synaptic activity, which produces the majority of the brain's energetic demands, triggers a rapid metabolic response including a characteristic shift towards aerobic glycolysis. Herein, astrocytically derived lactate appears to serve as an important metabolite to meet the extensive metabolic needs of activated neurons. Despite a wealth of literature characterizing lactate's role in mediating these acute metabo...
Source: Neurobiology of Learning and Memory - September 18, 2020 Category: Neurology Authors: Bingul D, Kalra K, Murata EM, Belser A, Dash MB Tags: Neurobiol Learn Mem Source Type: research

Thalamic nucleus reuniens regulates fear memory destabilization upon retrieval.
Abstract The neural circuit supporting aversive memory destabilization after retrieval includes the hippocampus, amygdala, and medial prefrontal cortex. The nucleus reuniens (NR) contributes to the functional interaction of these brain regions relevant to cognitive processing. However, the direct participation of this thalamic subregion in memory destabilization is yet to be investigated. The present study addressed this question in contextually fear-conditioned rats. Pre-reactivation infusion of the GABAA receptor agonist muscimol, the protein degradation inhibitor clasto-lactacystin β-lactone (β-lac), ...
Source: Neurobiology of Learning and Memory - September 17, 2020 Category: Neurology Authors: Troyner F, Jose Bertoglio L Tags: Neurobiol Learn Mem Source Type: research

Histone H2A.Z is required for androgen receptor-mediated effects on fear memory.
Abstract Epigenetic factors translate environmental signals into stable outcomes, but how they are influenced by regulators of plasticity remain unclear. We previously showed that androgen receptor overexpression inhibited fear memory in male mice and increased expression of the histone variant H2A.Z, a novel epigenetic regulator of memory. Here, we used conditional-inducible H2A.Z knockout mice to investigate how H2A.Z deletion influences androgenic regulation of fear memory. We showed that conditional inducible H2A.Z deletion blocked memory-enhancing effects of androgen depletion (induced by gonadectomy), and of...
Source: Neurobiology of Learning and Memory - September 7, 2020 Category: Neurology Authors: Ramzan F, Baumbach J, Monks AD, Zovkic IB Tags: Neurobiol Learn Mem Source Type: research

Retrieval of allocentric spatial memories is preserved up to thirty days and does not require higher brain metabolic demands.
In conclusion, our work adds information about the behavioural retrieval of an allocentric spatial reference task, suggesting that recovering spatial information seven, 15, and 30 days after acquisition is a simple task that does not require a high metabolic demand, in both male and female rats. PMID: 32891710 [PubMed - as supplied by publisher] (Source: Neurobiology of Learning and Memory)
Source: Neurobiology of Learning and Memory - September 2, 2020 Category: Neurology Authors: Zorzo C, Arias JL, Méndez M Tags: Neurobiol Learn Mem Source Type: research