Histone deacetylase inhibition differentially attenuates cue-induced reinstatement: An interaction of environment and acH3K9 expression in the dorsal striatum.
This study examined the effects of environmental condition on amphetamine self-administration, and whether drug-taking and drug-seeking behaviors could be influenced through inhibition of an epigenetic regulator, histone deacetylase (HDAC). Male rats reared for 30 days in enriched (EC), isolated (IC), or standard conditions (SC) prior to amphetamine (0.03, 0.05, 0.1 mg/kg/infusion, IV) self-administration, extinction, and reinstatement sessions. The HDAC inhibitor, Trichostatin A (TsA; 0.3 mg/kg, IV), was injected 30 min prior to operant sessions. After amphetamine-induced reinstatement (0.25 mg/kg, subcutaneous [s.c.]), t...
Source: Behavioral Neuroscience - July 25, 2019 Category: Neuroscience Source Type: research
NMDA receptors in the basolateral amygdala mediate acquisition and extinction of an amphetamine conditioned place preference.
Previous work from our laboratory has indicated that temporary inactivation of the basolateral amygdala (BLA) with bupivacaine blocks acquisition, consolidation, and retrieval of an amphetamine conditioned place preference (CPP). The present study was designed to extend this line of investigation by examining whether N-methyl-D-aspartate (NMDA) receptors in the BLA mediate acquisition and extinction of an amphetamine CPP. Adult male Long-Evans rats received bilateral intra-BLA injections of the NMDA receptor antagonist 2-amino-5-phosphonopentanoic acid (AP5; 1.25 μg, 2.5 μg, or 5.0 μg) or saline prior to each session of...
Source: Behavioral Neuroscience - July 11, 2019 Category: Neuroscience Source Type: research
Spatial judgment in Parkinson’s disease: Contributions of attentional and executive dysfunction.
Spatial judgment is impaired in Parkinson’s disease (PD), with previous research suggesting that disruptions in attention and executive function are likely contributors. If judgment of center places demands on frontal systems, performance on tests of attention/executive function may correlate with extent of bias in PD, and attentional disturbance may predict inconsistency in spatial judgment. The relation of spatial judgment to attention/executive function may differ for those with left-side versus right-side motor onset (LPD, RPD), reflecting effects of attentional lateralization. We assessed 42 RPD, 37 LPD, and 67 heal...
Source: Behavioral Neuroscience - July 11, 2019 Category: Neuroscience Source Type: research
Aged rats with intact memory show distinctive recruitment in cortical regions relative to young adults in a cue mismatch task.
Similar to elderly humans, aged Long–Evans rats exhibit individual differences in performance on tasks that critically depend on the medial temporal lobe memory system. Although reduced memory performance is common, close to half of aged rats in this outbred rodent population perform within the range of young subjects, exhibiting a stable behavioral phenotype that may signal a resilience to memory decline. Increasing evidence from research on aging in the Long–Evans study population supports the existence of adaptive neural change rather than avoidance of detrimental effects of aging on the brain, indicating a malleabi...
Source: Behavioral Neuroscience - June 27, 2019 Category: Neuroscience Source Type: research
Development of an “object category recognition” task for mice: Involvement of muscarinic acetylcholine receptors.
Recent research suggests that rats are capable of object categorization-like processes. To study whether mice possess similar abilities, we developed a spontaneous one-trial object category recognition (OCR) task. Based on the spontaneous object recognition paradigm, mice discriminated between two otherwise equally novel objects, one from a novel category and one from a studied category. During the sample phase, mice were exposed to two different exemplars from the same category. After a retention delay, they explored a third (i.e., novel) object from that sampled category and an object from a novel category in a choice ph...
Source: Behavioral Neuroscience - June 27, 2019 Category: Neuroscience Source Type: research
Gonadal hormone fluctuations do not affect the expression or extinction of fear-potentiated startle in female rats.
We report that neither the expression nor extinction of fear-potentiated startle differed in rats given extinction training in proestrus compared to those in metestrus. Removal of the ovaries had no effect on fear acquisition or extinction learning as assessed by fear-potentiated startle. Finally, systemic injections of estradiol given to ovariectomized rats before extinction training had no effect on the expression of fear or the retention of extinction. Our findings suggest that the effect of female gonadal hormones on fear conditioning and extinction may depend on the measure of fear employed or by the parameters used t...
Source: Behavioral Neuroscience - June 27, 2019 Category: Neuroscience Source Type: research
Anxiety process “theta” biomarker in the stop signal task eliminated by a preceding relaxation test.
Anxiety disorders are currently the most prevalent psychiatric diseases in Europe and the United States, the 6th highest cause of years of life lived with disability, and so a grave and ever-increasing burden on health care resources. Categorization of specific anxiety disorders is constantly evolving, but even the new Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5) manual uses symptom lists, not objective biomarkers. The DSM–5 and International Classification of Diseases (10th ed.) also aim for single diagnoses, but patients present with mixed symptoms that fit multiple diagnoses. In 1 step towa...
Source: Behavioral Neuroscience - June 20, 2019 Category: Neuroscience Source Type: research
Human anxiety-specific “theta” occurs with selective stopping and localizes to right inferior frontal gyrus.
Anxiety disorders have high prevalence and generate major disability. But they have poor treatment targeting because psychiatry lacks diagnostic biomarkers. Right frontal goal-conflict-specific-rhythmicity (GCSR) in the simple stop signal task appears homologous to hippocampal “theta” as an anxiety-process biomarker but is weak and transient. An anticipatory response inhibition task (ARIT) elicits strong subjective conflict and so might generate stronger GCSR. Healthy participants provided EEG during an ARIT, which allowed direct comparison of selective (left, SG; right, GS), and nonselective (both, SS) handed stopping...
Source: Behavioral Neuroscience - June 20, 2019 Category: Neuroscience Source Type: research
Operant conditioning prevents cell death in the adult rat dentate gyrus.
Thousands of new neurons are produced each day in the dentate gyrus of the adult mammalian hippocampus. However, the majority of those cells die within weeks of their birth. The most effective way to prevent this cell death is through effortful and successful learning. Myriad studies have revealed that classical conditioning and spatial learning can prevent this cell death. However, little research has examined whether acquisition of an operant conditioning task with an appetitive reward also increases the number of surviving cells. Therefore, the current study was conducted to determine whether conditioning with an operan...
Source: Behavioral Neuroscience - June 17, 2019 Category: Neuroscience Source Type: research
Timing is everything: Developmental differences in the effect of chronic corticosterone exposure on extinction retention.
Adolescence is noted as a time of “storm and stress.” In this developmental stage both rodents and humans exhibit an impairment in the extinction of learned fear; however, this impairment can be alleviated, at least in rodents, by increasing the amount of extinction training given or by administering the partial NMDA receptor agonist D-Cycloserine. In the present study we explored whether the benefits of these treatments would be reduced by chronic exogenous corticosterone (a commonly studied stress-related hormone). In 2 experiments, adolescent rats were given pairings of a white noise and shock (acquisition) and then...
Source: Behavioral Neuroscience - June 17, 2019 Category: Neuroscience Source Type: research
Bilateral postsubiculum lesions impair visual and nonvisual homing performance in rats.
Nearly all species rely on visual and nonvisual cues to guide navigation, and which ones they use depend on the environment and task demands. The postsubiculum (PoS) is a crucial brain region for the use of visual cues, but its role in the use of self-movement cues is less clear. We therefore evaluated rats’ navigational performance on a food-carrying task in light and in darkness in rats that had bilateral neurotoxic lesions of the PoS. Animals were trained postoperatively to exit a refuge and search for a food pellet, and carry it back to the refuge for consumption. In both light and darkness, control and PoS-lesioned ...
Source: Behavioral Neuroscience - June 6, 2019 Category: Neuroscience Source Type: research
A neural marker of the start-gun in interval timing: Onset N1P2.
Although the neural markers of interval timing have been widely studied, the events that determine the onset and offset of an interval have only recently started to gain attention. In the present study, I compare the predictions of the perceptual (preonset and start-gun) and decisional bias hypotheses with respect to onset N1P2 amplitude, the point of subjective equality (PSE) and delta/theta activity. The onsets of the comparison intervals (CIs) were manipulated to begin earlier, later, or on-time with regard to a standard interval (SI). Results supported the start-gun account by demonstrating an increase in the N1P2 ampl...
Source: Behavioral Neuroscience - June 6, 2019 Category: Neuroscience Source Type: research
The rat medial frontal cortex controls pace, but not breakpoint, in a progressive ratio licking task.
The medial frontal cortex (MFC) is crucial for selecting actions and evaluating their outcomes. Outcome monitoring may be triggered by rostral parts of the MFC, which contain neurons that are modulated by reward consumption and are necessary for the expression of relative reward value. Here, we examined if the MFC further has a role in the control of instrumental licking. We used a progressive ratio licking task in which rats had to make increasing numbers of licks to receive liquid sucrose rewards. We determined what measures of progressive ratio performance are sensitive to value by testing rats with rewards containing 0...
Source: Behavioral Neuroscience - June 6, 2019 Category: Neuroscience Source Type: research
Introduction to the special issue on neuroethology.
This special issue highlights some recent advances in neuroethology based on research presented at the 13th International Congress of Neuroethology and associated satellite symposia in Brisbane, Australia, on July 15–20, 2018. The discipline of neuroethology combines methods and concepts from ethology with those from neurobiology to develop a comparative analysis of the mechanisms of behavior that takes into account a species’ ecology and evolutionary history. In his 1951 book The Study of Instinct, Nobel Prize winner Niko Tinbergen called on ethologists and neurophysiologists to join forces to search for mechanisms of...
Source: Behavioral Neuroscience - May 30, 2019 Category: Neuroscience Source Type: research
Neuronal activation in orbitofrontal cortex subregions: Cfos expression following cue-induced reinstatement of cocaine-seeking behavior.
Cocaine-use disorders are characterized by repeated relapse to drug-seeking and drug-taking behavior following periods of abstinence. Former drug users display increased activation of the orbitofrontal cortex (OFC) in response to drug-related cues, and similar phenomena are also observed in rodent models of drug relapse. The lateral, but not medial, OFC functionally contributes to the maintenance of cue-drug associations; however, less is known about the role of the ventral OFC in this process. To examine the pattern of neuronal activation in OFC subregions in response to drug-associated cues, rats were trained to respond ...
Source: Behavioral Neuroscience - May 6, 2019 Category: Neuroscience Source Type: research
