Alterations in odor hedonics in the 5XFAD Alzheimer’s disease mouse model and the influence of sex.
Olfactory impairments, including deficits in odor detection, discrimination, recognition, and changes in odor hedonics, are reported in the early stages of Alzheimer’s disease (AD). Rodent models of AD display deficits in odor learning, detection, and discrimination—recapitulating the clinical condition. However, the impact of familial AD genetic mutations on odor hedonics is unknown. We tested 2-, 4-, and 6-month-old 5XFAD (Tg6799) mice in the 5-port odor multiple-choice task designed to assay a variety of odor-guided behaviors, including odor preferences/hedonics. We found that 5XFAD mice investigated odors longer th...
Source: Behavioral Neuroscience - August 6, 2020 Category: Neuroscience Source Type: research
Early life sleep disruption is a risk factor for increased ethanol drinking after acute footshock stress in prairie voles.
Early postnatal experiences are important for shaping the development of the stress response and may contribute to the later emergence of alcohol use disorders. We have previously found that early life sleep disruption impairs social development and alters GABA neurons in the brain of adult prairie voles, a socially monogamous rodent that displays natural ethanol preference in the laboratory. However, it is unclear whether these effects on social behavior are due, in part, to overall anhedonia and/or altered behavioral response to stress. To address this question, litters containing prairie vole pups were sleep disrupted b...
Source: Behavioral Neuroscience - July 23, 2020 Category: Neuroscience Source Type: research
Parametric investigation of social place preference in adolescent mice.
Social interaction promotes survival by helping animals to form stable and supportive groups. Additionally, maladaptive social behavior is a hallmark of disorders such as autism and schizophrenia. In many different animal species, including humans, social interaction can be inherently rewarding. Lately there has been growing interest in studying the neurobiological underpinnings of social interaction and learned social behavior in rodent behavioral models. One common procedure is conditioned place preference (CPP) to measure the rewarding effects of social interaction and social reward learning. Social CPP was originally u...
Source: Behavioral Neuroscience - July 16, 2020 Category: Neuroscience Source Type: research
Awake delta and theta-rhythmic hippocampal network modes during intermittent locomotor behaviors in the rat.
Delta-frequency network activity is commonly associated with sleep or behavioral disengagement accompanied by a dearth of cortical spiking, but delta in awake behaving animals is not well understood. We show that hippocampal (HC) synchronization in the delta frequency band (1–4 Hz) is related to animals’ locomotor behavior using detailed analyses of the HC local field potential (LFP) and simultaneous head- and body-tracking data. In contrast to running-speed modulation of the theta rhythm (6–10 Hz), delta was most prominent when animals were stationary or moving slowly, that is, when theta and fast gamma (65–120 Hz...
Source: Behavioral Neuroscience - July 16, 2020 Category: Neuroscience Source Type: research
Acute NMDA receptor antagonism impairs working memory performance but not attention in rats—Implications for the NMDAr hypofunction theory of schizophrenia.
Cognitive deficits in schizophrenia, which include impairments in working memory and attention, represent some of the most disabling symptoms of this complex psychiatric condition, and lack effective treatments. NMDA receptor (NMDAr) hypofunction is a strong candidate mechanism underlying schizophrenia pathophysiology, and has been modeled preclinically using acute administration of NMDAr antagonists to rodents to investigate biological mechanisms underpinning cognitive dysfunction. However, whether and how NMDAr hypofunction specifically influences all affected cognitive domains is unclear. Here we studied the effects of ...
Source: Behavioral Neuroscience - July 13, 2020 Category: Neuroscience Source Type: research
Partial integration of the components of value in anterior cingulate cortex.
Evaluation often involves integrating multiple determinants of value, such as the different possible outcomes in risky choice. A brain region can be placed either before or after a presumed evaluation stage by measuring how responses of its neurons depend on multiple determinants of value. A brain region could also, in principle, show partial integration, which would indicate that it occupies a middle position between (preevaluative) nonintegration and (postevaluative) full integration. Existing mathematical techniques cannot distinguish full from partial integration and therefore risk misidentifying regional function. Her...
Source: Behavioral Neuroscience - July 13, 2020 Category: Neuroscience Source Type: research
Coordination of hippocampal theta and gamma oscillations relative to spatial active avoidance reflects cognitive outcome after febrile status epilepticus.
Cognitive deficits may arise from a variety of genetic alterations and neurological insults that impair neural coding mechanisms and the routing of neural information underpinning learning and memory. Slow and medium gamma oscillations underpin memory recall and sensorimotor processing and represent dynamic inputs at CA1 synapses. Febrile status epilepticus (FSE) can lead to increased risk for temporal lobe epilepsy and enduring cognitive impairments. In a rodent model, we assessed how FSE alters hippocampal CA1 signals relative to spatial task performance and serve as a readout of synaptic input efficacy. The power of the...
Source: Behavioral Neuroscience - July 6, 2020 Category: Neuroscience Source Type: research
Investigation of the cortical activity during episodic future thinking in schizophrenia: A functional near-infrared spectroscopy study.
Episodic future thinking (EFT) refers to mental simulation of possible future events, a process that mostly depends on episodic memory (EM). EFT impairment in schizophrenia was proposed to disturb continuity in self-functioning. Schizophrenia patients are also impaired in EM as well as executive functions (EFs). In the present study, we aimed to clarify the relationship between EFT and memory functions in schizophrenia by assessing (a) whether a group of individuals with schizophrenia (schizophrenia group [SG]) who have relatively intact long-term memory functions differ from healthy controls (control group [CG]) in terms ...
Source: Behavioral Neuroscience - June 18, 2020 Category: Neuroscience Source Type: research
Reduced renewal of conditioned suppression following lesions of the dorsal hippocampus in male rats.
Extinguished responding will renew when the conditioned stimulus occurs outside the extinction context. Although studies of conditioned freezing have consistently demonstrated a role for the hippocampus in renewal, several studies have demonstrated intact renewal of conditioned suppression despite damage to the hippocampus (Frohardt, Guarraci, & Bouton, 2000; Todd, Jiang, DeAngeli, & Bucci, 2017; Wilson, Brooks, & Bouton, 1995). Because these prior studies have examined renewal when testing occurred in the original conditioning context (“Context A”), the present conditioned suppression experiments examined the role of ...
Source: Behavioral Neuroscience - June 11, 2020 Category: Neuroscience Source Type: research
Chemogenetic inhibition of dopaminergic projections to the nucleus accumbens has sexually dimorphic effects in the rat gambling task.
Women and men can differ in their propensity to take risks and develop impulse control and addiction disorders. Sexual dimorphisms in behavioral control by the mesolimbic dopaminergic reward system may underlie these phenomena, given its sensitivity to gonadal hormones. However, this is hard to test experimentally using humans. Using the rat gambling task (rGT), we investigated what impact acute inhibition of accumbal dopamine had on decision-making and impulsivity in animals of both sexes. We expressed an inhibitory designer receptor exclusively activated by designer drugs (hM4D[Gi]) in the accumbal dopaminergic efferents...
Source: Behavioral Neuroscience - June 11, 2020 Category: Neuroscience Source Type: research
Context-dependent odor learning requires the anterior olfactory nucleus.
We describe a distinct role for the AON in olfactory processing and conclude that early olfactory networks such as the olfactory bulb and AON function as multimodal integration networks rather than processing olfactory signals exclusively. (PsycInfo Database Record (c) 2020 APA, all rights reserved) (Source: Behavioral Neuroscience)
Source: Behavioral Neuroscience - May 7, 2020 Category: Neuroscience Source Type: research
A role for neurogenesis in probabilistic reward learning.
Rewards are often unreliable and optimal choice requires behavioral flexibility and learning about the probabilistic nature of uncertain rewards. Probabilistic learning occurs over multiple trials, often without conscious knowledge, and is traditionally associated with striatal function. While the hippocampus is classically recognized for its role in memory for individual experiences, recent work indicates that it is also involved in probabilistic forms of learning but little is known about the features that support such learning. We hypothesized that adult neurogenesis may be involved, because adult-born neurons contribut...
Source: Behavioral Neuroscience - May 7, 2020 Category: Neuroscience Source Type: research
An investigation into the nonlinear coupling between CA1 layers and the dentate gyrus.
Although the activity from the dentate gyrus is known to have strong connections with other hippocampal layers, the functionality of these connections, that is, the degree to which it drives activity in the downstream regions of the hippocampus, is not well understood. This question is particularly relevant for mesoscale localfield potential (LFP) rhythms such as gamma oscillations. Following the hypothesis that fundamental features of the LFP are consistent with turbulent dynamics, we investigate the crosslayer relationship between the CA1 layers and the dentate gyrus as a function of running speed. In agreement with prev...
Source: Behavioral Neuroscience - April 16, 2020 Category: Neuroscience Source Type: research
Gestational exposure to a ketogenic diet increases sociability in CD-1 mice.
Postnatal administration of high-fat, low-carbohydrate ketogenic diets (KDs) is an established and effective treatment option for refractory epilepsy, with more recently identified therapeutic potential across a wide range of preclinical models of neurological and psychiatric disorders. However, the impact of gestational exposure to a KD (GKD) on offspring development remains unclear. Previous work has found that GKD exposure reduces depression- and anxiety-like behaviors in CD-1 mice, whereas postnatal KD improves sociability in several different rodent models of autism. Here we examined how sociability is impacted by GKD...
Source: Behavioral Neuroscience - March 30, 2020 Category: Neuroscience Source Type: research
Phasic modulation of hippocampal synaptic plasticity by theta rhythm.
Theta rhythm and long-term potentiation (LTP) are 2 remarkable discoveries. The theta rhythm is an oscillatory neural activity of 3–10 Hz in the hippocampus. LTP is implicated as a cellular basis of memory, but the function of theta oscillation in memory is not clear. This review suggests that theta rhythm bestows optimal conditions for hippocampal LTP and memory encoding. Theta rhythm in hippocampal CA1 is generated mainly by 2 oscillating dipoles—somatic-inhibition and phase-shifted, distal dendritic excitation, with a smaller contribution by rhythmic proximal (CA3) excitation and distal inhibition. Our recent study ...
Source: Behavioral Neuroscience - January 9, 2020 Category: Neuroscience Source Type: research
