Serotonergic treatment normalizes midbrain dopaminergic neuron increase after periaqueductal gray stimulation
In this study, we further analysed our previous data on the effects of escitalopram (a selective serotonin reuptake inhibitor, SSRI) and buspirone (a 5-HT1A receptor partial agonist) on dlPAG-induced anticipatory fear behaviour in a rat model using freezing as a measure. We then attempted to unravel some of the interactions with dopamine signalling using tyrosine hydroxylase (TH) immunohistochemistry to probe the effects on dopaminergic neurons. We showed that acute treatment of escitalopram, but not buspirone, was effective in reducing anticipatory freezing behaviour, while chronic administrations of both drugs were effec...
Source: Anatomy and Embryology - June 27, 2020 Category: Anatomy Source Type: research

Morphology of the criminal brain: gray matter reductions are linked to antisocial behavior in offenders
AbstractAggression and psychopathy are multifaceted conditions determined interpersonal and antisocial factors. Only a few studies analyze the link between these separate factors and specific brain morphology distinctively. A voxel-based morphometry (VBM) analysis was performed on 27 violent offenders and 27 controls aiming to associate sub-features of aggressive and psychopathic behavior with specific gray matter volumes. Trait aggression was assessed using two self-report tests (Aggression Questionnaire, AQ, and Reactive –Proactive–Aggression Questionnaire, RPQ) and psychopathy with the Psychopathy Checklist-...
Source: Anatomy and Embryology - June 26, 2020 Category: Anatomy Source Type: research

Direct administration of ifenprodil and citalopram into the nucleus accumbens inhibits cue-induced nicotine seeking and associated glutamatergic plasticity
AbstractNicotine use disorder has been associated with glutamatergic alterations within the basal ganglia that might contribute to relapse. Specifically, initiation of cue-induced nicotine seeking produces rapid, transient synaptic potentiation (t-SP) in nucleus accumbens core (NAcore) medium spiny neurons (MSNs), defined as increases in spine head diameter and AMPA to NMDA current ratios (A/N). Ifenprodil, which inhibits nicotine reinstatement when administered systemically, antagonizes GluN2B-containing NMDA receptors, has affinity for serotonin receptors, and blocks serotonin transporters (SERT). The mechanisms underlyi...
Source: Anatomy and Embryology - June 26, 2020 Category: Anatomy Source Type: research

Recursive music elucidates neural mechanisms supporting the generation and detection of melodic hierarchies
AbstractThe ability to generate complex hierarchical structures is a crucial component of human cognition which can be expressed in the musical domain in the form of hierarchical melodic relations. The neural underpinnings of this ability have been investigated by comparing the perception of well-formed melodies with unexpected sequences of tones. However, these contrasts do not target specifically the representation of rules generating hierarchical structure. Here, we present a novel paradigm in which identical melodic sequences are generated in four steps, according to three different rules: The Recursive rule, generatin...
Source: Anatomy and Embryology - June 26, 2020 Category: Anatomy Source Type: research

Postnatal exposure to an acoustically enriched environment alters the morphology of neurons in the adult rat auditory system
AbstractThe structure of neurons in the central auditory system is vulnerable to various kinds of acoustic exposures during the critical postnatal developmental period. Here we explored long-term effects of exposure to an acoustically enriched environment (AEE) during the third and fourth weeks of the postnatal period in rat pups. AEE consisted of a spectrally and temporally modulated sound of moderate intensity, reinforced by a behavioral paradigm. At the age of 3 –6 months, a Golgi–Cox staining was used to evaluate the morphology of neurons in the inferior colliculus (IC), the medial geniculate body (MGB...
Source: Anatomy and Embryology - June 25, 2020 Category: Anatomy Source Type: research

A radial histogenetic model of the mouse pallial amygdala
AbstractConventional anatomic models of the rodent (mammalian) amygdala are based on section planes oblique to its intrinsic radial glial organization. As a result, we still lack a model of amygdalar histogenesis in terms of radial units (progenitor domains and related radial migration and layering patterns). A radial model of the mouse pallial amygdala is first offered here, based on three logical steps: (1) analysis of amygdalar radial structure in variously discriminative genoarchitectonic material, using an optimalad hoc section plane; (2) testing preliminary models with experiments labelling at the brain surface singl...
Source: Anatomy and Embryology - June 24, 2020 Category: Anatomy Source Type: research

Aging impairs perceptual decision-making in mice: integrating computational and neurobiological approaches
This study investigated the latent variables of the decision process using the hierarchical drift –diffusion model (HDDM). Neurobiological correlates of these processes were examined via immunohistochemistry. Young (n = 11, 4 months old), adult (n = 10, 10 months old), and old (n = 10, 18 months old) mice were tested in a perceptual decision-making task (i.e. two-alternative forced-choice; 2AFC). Observed data showed that there was an age-dependent decrease in the accuracy rate of old mice while response times were comparable between age groups. HDDM results re...
Source: Anatomy and Embryology - June 22, 2020 Category: Anatomy Source Type: research

Serotonergic innervation of the auditory midbrain: dorsal raphe subregions differentially project to the auditory midbrain in male and female mice
AbstractIn the auditory inferior colliculus (IC), serotonin reflects features of context including the valence of social interactions, stressful events, and prior social experience. However, within the dorsal raphe nucleus (DRN; B6  + B7), the source of serotonergic projections to the IC has not been resolved at the level of DRN subregions. Additionally, few studies have investigated which DRN subregions are engaged during naturalistic, sensory-driven social behaviors. We employ traditional, retrograde tract-tracing approa ches to comprehensively map the topographic extent of DRN-IC projection neurons in male...
Source: Anatomy and Embryology - June 19, 2020 Category: Anatomy Source Type: research

Reward-related dynamical coupling between basolateral amygdala and nucleus accumbens
AbstractRecognizing reward-related stimuli is crucial for survival. Neuronal projections from the basolateral amygdala (BLA) to the nucleus accumbens (NAc) play an important role in processing reward-related cues. Previous studies revealed synchronization between distant brain regions in reward-sensitive neurocircuits; however, whether the NAc synchronizes with the BLA is unknown. Here, we recorded local field potentials simultaneously from the BLA and NAc of rats during social preference tests and an appetitive conditioning test in which explicit stimuli were associated with food. BLA-NAc coherence in the theta band (5 &n...
Source: Anatomy and Embryology - June 18, 2020 Category: Anatomy Source Type: research

Effects of transcranial direct current stimulation of left and right inferior frontal gyrus on creative divergent thinking are moderated by changes in inhibition control
AbstractDivergent thinking (DT) as one component of creativity is the ability to search for multiple solutions to a single problem and is reliably tested with the Alternative Uses Task (AUT). DT depends on activity in the inferior frontal gyrus (IFG), a prefrontal region that has also been associated with inhibitory control (IC). Experimentally manipulating IC through transcranial direct current stimulation (tDCS) led to alterations in DT. Here, we aimed at further examining such potential mediating effects of IC on DT (measured as flexibility, fluency, and originality in the AUT) by modulating IC tDCS. Participants receiv...
Source: Anatomy and Embryology - June 17, 2020 Category: Anatomy Source Type: research

Topological atlas of the hypothalamus in adult rhesus monkey
AbstractThe prosomeric model explains the embryological development of the central nervous system (CNS) shared by all vertebrates as a Bauplan. As a primary event, the early neural plate is patterned by intersecting longitudinal plates and transverse segments, forming a mosaic of progenitor units. The hypothalamus is specified by three prosomeres (hp1, hp2, and the acroterminal domain) of the secondary prosencephalon with corresponding alar and basal plate parts, which develop apart from the diencephalon. Mounting evidence suggests that progenitor units within alar and basal plate parts of hp1 and hp2 give rise to distinct...
Source: Anatomy and Embryology - June 16, 2020 Category: Anatomy Source Type: research

The visual white matter connecting human area prostriata and the thalamus is retinotopically organized
AbstractThe human visual system is capable of processing visual information from fovea to the far peripheral visual field. Recent fMRI studies have shown a full and detailed retinotopic map in area prostriata, located ventro-dorsally and anterior to the calcarine sulcus along the parieto-occipital sulcus with strong preference for peripheral and wide-field stimulation. Here, we report the anatomical pattern of white matter connections between area prostriata and the thalamus encompassing the lateral geniculate nucleus (LGN). To this end, we developed and utilized an automated pipeline comprising a series of Apps that run o...
Source: Anatomy and Embryology - June 13, 2020 Category: Anatomy Source Type: research

Long-term potentiation of the nucleus reuniens and entorhinal cortex to CA1 distal dendritic synapses in mice
AbstractThe present study investigated the short-term and long-term synaptic plasticity of excitatory synapses formed by the nucleus reuniens (RE) and entorhinal cortex (EC) on the distal apical dendrites of CA1 pyramidal cells. RE-CA1 synapses are implicated in memory involving the hippocampus and medial prefrontal cortex. Current source density (CSD) analysis was used to identify excitatory and inhibitory currents following stimulation of RE or medial perforant path (MPP) in urethane-anesthetized mice in vivo. At the distal apical dendrites, RE evoked an initial excitatory sink followed by inhibitory sources at short (~ ...
Source: Anatomy and Embryology - June 13, 2020 Category: Anatomy Source Type: research

Glutamic acid decarboxylase 67 haplodeficiency in mice: consequences of postweaning social isolation on behavior and changes in brain neurochemical systems
AbstractReductions of glutamate acid decarboxylase (GAD67) and subsequent GABA levels have been consistently observed in neuropsychiatric disorders like schizophrenia and depression, but it has remained unclear how GABAergic dysfunction contributes to different symptoms of the diseases. To address this issue, we investigated male mice haplodeficient for GAD67 (GAD67+/GFP mice), which showed a reduced social interaction, social dominance and increased immobility in the forced swim test. No differences were found in rotarod performance and sensorimotor gating. We also addressed potential effects of social deprivation, which ...
Source: Anatomy and Embryology - June 8, 2020 Category: Anatomy Source Type: research

Association between human gray matter metabotropic glutamate receptor-5 availability in vivo and white matter properties: a [ 11 C]ABP688 PET and diffusion tensor imaging study
We examined the relationship in healthy individuals between GM mGluR5 availability measured in vivo using [11C]ABP688 positron emission tomography (PET) and WM properties measured  as fractional anisotropy (FA) using diffusion tensor imaging (DTI). Twenty-three healthy volunteers underwent this multimodal imaging. We calculated mGluR5 availability, [11C]ABP688 binding potential (BPND), using the simplified reference tissue model, and generated DTI FA maps using FMRIB ’s Diffusion Toolbox (FDT) along with Tract-Based Spatial Statistics (TBSS). To investigate the relationship between mGluR5 availability and FA, we...
Source: Anatomy and Embryology - June 3, 2020 Category: Anatomy Source Type: research

Effects of basal forebrain stimulation on the vibrotactile responses of neurons from the hindpaw representation in the rat SI cortex
AbstractBasal forebrain (BF) cholinergic system is important for attention and modulates sensory processing. We focused on the hindpaw representation in rat primary somatosensory cortex (S1), which receives inputs related to mechanoreceptors identical to those in human glabrous skin. Spike data were recorded from S1 tactile neurons (n = 87) with (ON condition: 0.5-ms bipolar current pulses at 100 Hz; amplitude 50 μA, duration 0.5 s at each trial) and without (OFF condition) electrical stimulation of BF in anesthetized rats. We expected that prior activation of BF would induce changes in the ...
Source: Anatomy and Embryology - June 3, 2020 Category: Anatomy Source Type: research

Hemodynamic latency is associated with reduced intelligence across the lifespan: an fMRI DCM study of aging, cerebrovascular integrity, and cognitive ability
AbstractChanges in neurovascular coupling are associated with both Alzheimer ’s disease and vascular dementia in later life, but this may be confounded by cerebrovascular risk. We hypothesized that hemodynamic latency would be associated with reduced cognitive functioning across the lifespan, holding constant demographic and cerebrovascular risk. In 387 adults aged 18–85 (mean = 48.82), dynamic causal modeling was used to estimate the hemodynamic response function in the left and right V1 and V3-ventral regions of the visual cortex in response to a simple checkerboard block design stimulus with mi...
Source: Anatomy and Embryology - May 30, 2020 Category: Anatomy Source Type: research

BTBD9 and dopaminergic dysfunction in the pathogenesis of restless legs syndrome
AbstractRestless legs syndrome (RLS) is characterized by an urge to move legs, usually accompanied by uncomfortable sensations. RLS symptoms generally happen at night and can be relieved by movements. Genetic studies have linked polymorphisms inBTBD9 to a higher risk of RLS. Knockout ofBTBD9 homolog in mice (Btbd9) and fly results in RLS-like phenotypes. A dysfunctional dopaminergic system is associated with RLS. However, the function ofBTBD9 in the dopaminergic system and RLS is not clear. Here, we made use of the simpleCaenorhabditis elegans nervous system. Loss ofhpo-9, the worm homolog ofBTBD9, resulted in hyperactive ...
Source: Anatomy and Embryology - May 28, 2020 Category: Anatomy Source Type: research

Dorsal prefrontal and premotor cortex of the ferret as defined by distinctive patterns of thalamo-cortical projections
AbstractRecent studies of the neurobiology of the dorsal frontal cortex (FC) of the ferret have illuminated its key role in the attention network, top-down cognitive control of sensory processing, and goal directed behavior. To elucidate the neuroanatomical regions of the dorsal FC, and delineate the boundary between premotor cortex (PMC) and dorsal prefrontal cortex (dPFC), we placed retrograde tracers in adult ferret dorsal FC anterior to primary motor cortex and analyzed thalamo-cortical connectivity. Cyto- and myeloarchitectural differences across dorsal FC and the distinctive projection patterns from thalamic nuclei, ...
Source: Anatomy and Embryology - May 26, 2020 Category: Anatomy Source Type: research

The association between prenatal endocrine-disrupting chemical exposure and altered resting-state brain fMRI in teenagers
This study aimed to investigate a relationship of the concentration of prenatal EDCs and brain function in teenagers. We recruited 59 mother –child pairs during the third trimester of pregnancy, and collected and examined the concentration of EDCs, such as heavy metals, phthalates and perfluoroalkyl substances (PFASs), in maternal urine and serum. Resting-state functional magnetic resonance imaging (rs-fMRI) data were collected in teen agers 13–16 years of age, and fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo) were performed to find the association between matern...
Source: Anatomy and Embryology - May 25, 2020 Category: Anatomy Source Type: research

Karl Zilles (1944 –2020): a personal tribute
(Source: Anatomy and Embryology)
Source: Anatomy and Embryology - May 24, 2020 Category: Anatomy Source Type: research

A systematic comparison of structural-, structural connectivity-, and functional connectivity-based thalamus parcellation techniques
We present the first systematic qualitative and quantitative comparison of these methods. The results show that DTI parcellation agrees more with structural parcellation in the larger thalamic nuclei, while rsfMRI parcellation agrees more with structural parcellation in the smaller nuclei. Structural parcellation is the most accurate in the delineation of small structures such as the habenular, antero-ventral, and medial geniculate nuclei. (Source: Anatomy and Embryology)
Source: Anatomy and Embryology - May 21, 2020 Category: Anatomy Source Type: research

Perspectives given by structural connectivity bridge the gap between structure and function
(Source: Anatomy and Embryology)
Source: Anatomy and Embryology - May 15, 2020 Category: Anatomy Source Type: research

Lack of M 4 muscarinic receptors in the striatum, thalamus and intergeniculate leaflet alters the biological rhythm of locomotor activity in mice
AbstractThe deletion of M4 muscarinic receptors (MRs) changes biological rhythm parameters in females. Here, we searched for the mechanisms responsible for these changes. We performed biological rhythm analysis in two experiments: in experiment 1, the mice [C57Bl/6NTac (WT) and M4 MR −/− mice (KO)] were first exposed to a standard LD regime (12/12-h light/dark cycle) for 8 days and then subsequently exposed to constant darkness (for 24 h/day, DD regime) for another 16 days. In experiment 2, the mice (after the standard LD regime) were exposed to the DD regime and to one l ight pulse (zeitgeber ti...
Source: Anatomy and Embryology - May 14, 2020 Category: Anatomy Source Type: research

Obesity induced by Borna disease virus in rats: key roles of hypothalamic fast-acting neurotransmitters and inflammatory infiltrates
In conclusion, the study provided clear evidence that BDV-1 induced obesity in the rat model is the result of interdependent structural and functional metabolic changes. They can be explained by an immunologically induced hypothalamic microcirculation-defect, combined with a disturba nce of neurotransmitter regulatory systems. The proposed mechanism may also have implications for human health. BDV-1 infection has been frequently found in depressive patients. Independently, comorbidity between depression and obesity has been reported, either. Future studies should address the exc iting question of whether BDV-1 infection co...
Source: Anatomy and Embryology - May 11, 2020 Category: Anatomy Source Type: research

The impact of phantom decoys on the neural processing of valuation
AbstractRational decision theories posit that good choices should be based solely on information that is relevant to the choice at hand. However, introducing an inferior option that would never be chosen can influence choices among other relevant options, known as decoy effect. We used functional magnetic resonance imaging (fMRI) combined with a simple gambling task to investigate the neural signature of decision-making in or against the influence of the decoy effect in inferior and superior phantom decoy conditions. The fMRI results show that compared with choosing against the influence of the dominated phantom inferior o...
Source: Anatomy and Embryology - May 8, 2020 Category: Anatomy Source Type: research

Untangling the dorsal diencephalic conduction system: a review of structure and function of the stria medullaris, habenula and fasciculus retroflexus
AbstractThe often-overlooked dorsal diencephalic conduction system (DDCS) is a highly conserved pathway linking the basal forebrain and the monoaminergic brainstem. It consists of three key structures; the stria medullaris, the habenula and the fasciculus retroflexus. The first component of the DDCS, the stria medullaris, is a discrete bilateral tract composed of fibers from the basal forebrain that terminate in the triangular eminence of the stalk of the pineal gland, known as the habenula. The habenula acts as a relay hub where incoming signals from the stria medullaris are processed and subsequently relayed to the midbr...
Source: Anatomy and Embryology - May 4, 2020 Category: Anatomy Source Type: research

The NanoZoomer artificial intelligence connectomics pipeline for tracer injection studies of the marmoset brain
We describe our connectomics pipeline for processing anterograde tracer injection data for the brain of the common marmoset (Callithrix jacchus). Brain sections were imaged using a batch slide scanner (NanoZoomer 2.0-HT) and we used artificial intelligence to precisely segment the tracer signal from the background in the fluorescence images. The shape of each brain was reconstructed by reference to a block-face and all data were mapped into a common 3D brain space with atlas and 2D cortical flat map. To overcome the effect of using a single template atlas to specify cortical boundaries, brains were cyto- and myelo-architec...
Source: Anatomy and Embryology - May 4, 2020 Category: Anatomy Source Type: research

Probabilistic tractography in the ventrolateral thalamic nucleus: cerebellar and pallidal connections
In this study we performed a (a) qualitative and (b) quantitative examination of VL-cerebellar and VL-pallidal pathways and compared the probability distributions between both projection fields in the VL after an (I) atlas-based and (II) manual-based segmentation procedure. Both procedures led to high congruent results of cerebellar and pallidal connectivity distributions: the maximum of pallidal projections was located in anterior and medial parts of the VL nucleus, wher eas cerebellar connectivity was more located in lateral and posterior parts. The median connectivity for cerebellar connections in both approaches (manua...
Source: Anatomy and Embryology - May 3, 2020 Category: Anatomy Source Type: research

Investigating inhibition deficit in schizophrenia using task-modulated brain networks
AbstractSchizophrenia subjects have shown deficits of inhibition in conditions such as a stop signal task. The stop signal response time (SSRT) is consistently longer compared with healthy controls, and is accompanied by decreased brain activations in the right inferior frontal gyrus. However, as to how the response inhibition function is supported by distributed brain networks, and whether such networks are altered in schizophrenia are largely unknown. We analyzed functional MRI data of a stop signal task from 44 schizophrenia patients and 44 matched controls, and performed whole-brain psychophysiological interaction anal...
Source: Anatomy and Embryology - April 30, 2020 Category: Anatomy Source Type: research

Central autonomic network functional connectivity: correlation with baroreflex function and cardiovascular variability in older adults
AbstractBaroreflex regulates short-term cardiovascular variability via the autonomic neural system. The contributions of the central autonomic system to the baroreflex regulations of arterial blood pressure (BP) and heart rate have been reported in young healthy adults, but not in older adults. Therefore, we investigated the association between the high-level central autonomic network (CAN) connectivity and baroreflex sensitivity (BRS) under a resting condition in a healthy older population. Twenty-two older adults (68  ± 8 years old) underwent BRS assessment using the modified Oxford and transfer...
Source: Anatomy and Embryology - April 30, 2020 Category: Anatomy Source Type: research

The effect of intrinsic and extrinsic motivation on memory formation: insight from behavioral and imaging study
AbstractMotivation can be generated intrinsically or extrinsically, and both kinds of motivation show similar facilitatory effects on memory. However, effects of extrinsic and intrinsic motivation on memory formation have not been studied in combination and thus, it is unknown whether they interact and how such interplay is neurally implemented. In the present study, both extrinsic monetary reward and intrinsic curiosity enhanced memory performance, without evidence for an interaction. Functional magnetic resonance imaging revealed that curiosity-driven activity in the ventral striatal reward network appears to work cooper...
Source: Anatomy and Embryology - April 29, 2020 Category: Anatomy Source Type: research

Spatiotemporal dynamics of auditory information processing in the insular cortex: an intracranial EEG study using an oddball paradigm
AbstractFunctional neuroimaging studies using auditory stimuli consistently show activation of the insular cortex. However, due to the limited temporal resolution of non-invasive neuroimaging techniques, the role(s) of the insula in auditory processing remains unclear. As the anterior insula (aI) and the posterior insula (pI) have different connections and are thought to be functionally distinct, it is likely that these two areas contribute differently to auditory processing. Our study examines the spatiotemporal dynamics of auditory processing in the insula using intracranial electroencephalography (EEG). Eight epileptic ...
Source: Anatomy and Embryology - April 28, 2020 Category: Anatomy Source Type: research

The occipital face area is causally involved in identity-related visual-semantic associations
AbstractFaces are processed in a network of areas within regions of the ventral visual stream. However, familiar faces typically are characterized by additional associated information, such as episodic memories or semantic biographical information as well. The acquisition of such non-sensory, identity-specific knowledge plays a crucial role in our ability to recognize and identify someone we know. The occipital face area (OFA), an early part of the core face-processing network, is recently found to be involved in the formation of identity-specific memory traces but it is currently unclear if this role is limited to unimoda...
Source: Anatomy and Embryology - April 27, 2020 Category: Anatomy Source Type: research

Personality factors and cerebral glucose metabolism in community-dwelling older adults
AbstractPersonality factors have been associated with Alzheimer ’s disease (AD) and dementia, but they have not been examined against markers of regional brain glucose metabolism (a primary measure of brain functioning) in older adults without clinically diagnosed cognitive impairment. The relationship between personality factors derived from the five-factor m odel and cerebral glucose metabolism determined using positron emission tomography (PET) with [18F]-2-fluoro-2-deoxy-d-glucose (18F-FDG-PET) was examined in a cohort of 237 non-demented, community-dwelling older adults aged 60 –89 years (M &pl...
Source: Anatomy and Embryology - April 27, 2020 Category: Anatomy Source Type: research

Brain-wide resting-state connectivity regulation by the hippocampus and medial prefrontal cortex is associated with fluid intelligence
AbstractThe connectivity hub property of the hippocampus (HIP) and the medial prefrontal cortex (MPFC) is essential for their widespread involvement in cognition; however, the cooperation mechanism between them is far from clear. Herein, using resting-state functional MRI and Gaussian Bayesian network to describe the directed organizing architecture of the HIP –MPFC pathway with regions in the brain, we demonstrated that the HIP and the MPFC have central roles as the driving hub and aggregating hub, respectively. The status of the HIP and the MPFC is dominant in communications between the HIP and the default-mode net...
Source: Anatomy and Embryology - April 24, 2020 Category: Anatomy Source Type: research

White matter characteristics of motor, sensory and interhemispheric tracts underlying impaired upper limb function in children with unilateral cerebral palsy
This study explored the role of lesion timing (periventricular white matter versus cortical and deep grey matter lesions) and type of corticospinal tract (CST) wiring pattern (contralateral, bilateral, ipsilateral) on white matter characteristics of the CST, medial lemniscus, superior thalamic radiations and sensorimotor transcallosal fibers in children with unilateral cerebral palsy (CP), and examined the  association with upper limb function. Thirty-four children (mean age 10 years 7 months ± 2 years 3 months) with unilateral CP underwent a comprehensive upper limb evaluation and diffusion weigh...
Source: Anatomy and Embryology - April 21, 2020 Category: Anatomy Source Type: research

Mapping tracts in the human subthalamic area by 11.7T ex vivo diffusion tensor imaging
AbstractThe cortico-basal ganglia-thalamo-cortical feedback loops that consist of distinct white matter pathways are important for understanding in vivo imaging studies of functional and anatomical connectivity, and for localizing subthalamic white matter structures in surgical approaches for movement disorders, such as Parkinson ’s disease. Connectomic analysis in animals has identified fiber connections between the basal ganglia and thalamus, which pass through the fields of Forel, where other fiber pathways related to motor, sensory, and cognitive functions co-exist. We now report these pathways in the human brain...
Source: Anatomy and Embryology - April 17, 2020 Category: Anatomy Source Type: research

Association between diffusivity measures and language and cognitive-control abilities from early toddler ’s age to childhood
AbstractExtensive improvements in executive functions and language abilities are accompanied by changes in functional connections within the brain and in gray and white matter during the first few years of life. Diffusion tensor imaging provides a unique look into pediatric brain anatomy and critical information regarding white-matter development. The aims of the current study were to investigate the variability in diffusion indices in language and cognitive white-matter tracts, hemispheric lateralization, and how diffusion measures are related to age, language and cognitive abilities from early toddler age to early childh...
Source: Anatomy and Embryology - April 8, 2020 Category: Anatomy Source Type: research

GABAergic and non-GABAergic subpopulations of Kv3.1b-expressing neurons in macaque V2 and MT: laminar distributions and proportion of total neuronal population
AbstractThe Kv3.1b potassium channel subunit, which facilitates the fast-spiking phenotype characteristic of parvalbumin (PV)-expressing inhibitory interneurons, is also expressed by subpopulations of excitatory neurons in macaque cortex. We have previously shown that V1 neurons expressing Kv3.1b but not PV or GABA were largely concentrated within layers 4C α and 4B of V1, suggesting laminar or pathway specificity. In the current study, the distribution and pattern of co-immunoreactivity of GABA, PV, and Kv3.1b across layers in extrastriate cortical areas V2 and MT of the macaque monkey were measured using the same t...
Source: Anatomy and Embryology - April 7, 2020 Category: Anatomy Source Type: research

Spatial organization of occipital white matter tracts in the common marmoset
AbstractThe primate brain contains a large number of interconnected visual areas, whose spatial organization and intracortical projections show a high level of conservation across species. One fiber pathway of recent interest is the vertical occipital fasciculus (VOF), which is thought to support communication between dorsal and ventral visual areas in the occipital lobe. A recent comparative diffusion MRI (dMRI) study reported that the VOF in the macaque brain bears a similar topology to that of the human, running superficial and roughly perpendicular to the optic radiation. The present study reports a comparative investi...
Source: Anatomy and Embryology - April 6, 2020 Category: Anatomy Source Type: research

ALE meta-analysis, its role in node identification and the effects on estimates of local network organization
AbstractFunctional connectivity analyses for task-based fMRI data are generally preceded by methods for identification of network nodes. As there is no generalcanonical approach to identifying network nodes, different identification techniques may exert different effects on inferences drawn regarding functional network properties. Here, we compared the impact of two different node identification techniques on estimates of local node importance (based on Degree Centrality, DC) in two working memory domains: verbal and visual. The two techniques compared were the commonly used Activation Likelihood Estimate (ALE) technique (...
Source: Anatomy and Embryology - April 3, 2020 Category: Anatomy Source Type: research

In vivo reduction of striatal D1R by RNA interference alters expression of D1R signaling-related proteins and enhances methamphetamine addiction in male rats
This study sought to determine if reducing dopamine D1 receptor (D1R) expression in the dorsal striatum (DS) via RNA-interference alters methamphetamine self-administration. A lentiviral construct containing a short hairpin RNA (shRNA) was used to knock down D1R expression (D1RshRNA). D1RshRNA in male rats increased responding for methamphetamine (i.v.) under a fixed-ratio schedule in an extended access paradigm, compared to D1R-intact rats. D1RshRNA also produced a vertical shift in a dose –response paradigm and enhanced responding for methamphetamine in a progressive-ratio schedule, generating a drug-vulnerable phe...
Source: Anatomy and Embryology - April 3, 2020 Category: Anatomy Source Type: research

Ex vivo diffusion-weighted MRI tractography of the G öttingen minipig limbic system
This study aims to provide a high-quality ex vivo diffusion-weighted MRI (DWI) tractographic overview of the G öttingen minipig limbic system pathways, which are currently not well described. This may facilitate future translational large animal studies. The study used previously obtained post-mortem DWI scans in 3 female Göttingen minipigs aging 11–15 months. The tractography performed on the DWI data set was made using a probabilistic algorithm, and regions of interest (ROIs) were defined in accordance with a histological atlas. The investigated pathways included the fornix, mammillothalamic tract, s...
Source: Anatomy and Embryology - April 3, 2020 Category: Anatomy Source Type: research

Dissociation of somatostatin and parvalbumin interneurons circuit dysfunctions underlying hippocampal theta and gamma oscillations impaired by amyloid β oligomers in vivo
AbstractAccumulation of amyloid β oligomers (AβO) in Alzheimer’s disease (AD) impairs hippocampal theta and gamma oscillations. These oscillations are important in memory functions and depend on distinct subtypes of hippocampal interneurons such as somatostatin-positive (SST) and parvalbumin-positive (PV) interneurons. Here, w e investigated whether AβO causes dysfunctions in SST and PV interneurons by optogenetically manipulating them during theta and gamma oscillations in vivo in AβO-injected SST-Cre or PV-Cre mice. Hippocampal in vivo multi-electrode recordings revealed that optogenetic activat...
Source: Anatomy and Embryology - April 1, 2020 Category: Anatomy Source Type: research

Altered brain white matter connectome in children and adolescents with prenatal alcohol exposure
AbstractDiffuson tensor imaging (DTI) has demonstrated widespread alterations of brain white matter structure in children with prenatal alcohol exposure (PAE), yet it remains unclear how these alterations affect the structural brain network as a whole. The present study aimed to examine changes in the DTI-based structural connectome in children and adolescents with PAE compared to unexposed controls. Participants were 121 children and adolescents with PAE (51 females) and 119 typically-developing controls (49 females) aged 5 –18 years with DTI data collected at one of four research centers across Canada. Graph-t...
Source: Anatomy and Embryology - April 1, 2020 Category: Anatomy Source Type: research

Colocalized neurotransmitters in the hindbrain cooperate in adaptation to chronic hypernatremia
AbstractChronic hypernatremia activates the central osmoregulatory mechanisms and inhibits the function of the hypothalamic –pituitary–adrenal (HPA) axis. Noradrenaline (NE) release into the periventricular anteroventral third ventricle region (AV3V), the supraoptic (SON) and hypothalamic paraventricular nuclei (PVN) from efferents of the caudal ventrolateral (cVLM) and dorsomedial (cDMM) medulla has been shown to be essential for the hypernatremia-evoked responses and for the HPA response to acute restraint. Notably, the medullary NE cell groups highly coexpress prolactin-releasing peptide (PrRP) and nesfatin-...
Source: Anatomy and Embryology - March 21, 2020 Category: Anatomy Source Type: research

Decreased density of cholinergic interneurons in striatal territories in Williams syndrome
AbstractWilliams syndrome (WS) is a rare neurodevelopmental disorder caused by the hemideletion of approximately 25 –28 genes at 7q11.23. Its unusual social and cognitive phenotype is most strikingly characterized by the disinhibition of social behavior, in addition to reduced global IQ, with a relative sparing of language ability. Hypersociality and increased social approach behavior in WS may represent a uniq ue inability to inhibit responses to specific social stimuli, which is likely associated with abnormalities of frontostriatal circuitry. The striatum is characterized by a diversity of interneuron subtypes, in...
Source: Anatomy and Embryology - March 18, 2020 Category: Anatomy Source Type: research

Sources and lesion-induced changes of VEGF expression in brainstem motoneurons
In conclusion, the low VEGF expression observed in glial cells suggests that these cells are not the main source of VEGF for brainstem motoneurons. Therefore, the higher VEGF expression observed in motoneurons innervating extraocular muscles is likely due either to the fact that this factor is more avidly taken up from the target muscles, in basal conditions, or is produced by these motoneurons themselves, and acts in an autocrine manner after axotomy. (Source: Anatomy and Embryology)
Source: Anatomy and Embryology - March 18, 2020 Category: Anatomy Source Type: research

The role of diffusion tractography in refining glial tumor resection
AbstractPrimary brain tumors are notoriously hard to resect surgically. Due to their infiltrative nature, finding the optimal resection boundary without damaging healthy tissue can be challenging. One potential tool to help make this decision is diffusion-weighted magnetic resonance imaging (dMRI) tractography. dMRI exploits the diffusion of water molecule along axons to generate a 3D modelization of the white matter bundles in the brain. This feature is particularly useful to visualize how a tumor affects its surrounding white matter and plan a surgical path. This paper reviews the different ways in which dMRI can be used...
Source: Anatomy and Embryology - March 16, 2020 Category: Anatomy Source Type: research