Sex Differences and the Impact of Chronic Stress and Recovery on Instrumental Learning.

We have previously shown that 21-day chronic restraint stress impacts instrumental learning, but overall few studies have examined sex differences on the impact of stress on learning. We further examined sex differences in response to extended 42-day chronic stress on instrumental learning, as well as recovery from chronic stress. Rats were tested in aversive training tasks with or without prior appetitive experience, and daily body weight data was collected as an index of stress.

Mild Transient Hypercapnia as a Novel Fear Conditioning Stimulus Allowing Re-Exposure during Sleep.

Introduction: Studies suggest that sleep plays a role in traumatic memories and that treatment of sleep disorders may help alleviate symptoms of posttraumatic stress disorder. Fear-conditioning paradigms in rodents are used to investigate causal mechanisms of fear acquisition and the relationship between sleep and posttraumatic behaviors. We developed a novel conditioning stimulus (CS) that evoked fear and was subsequently used to study re-exposure to the CS during sleep.

Obesity accentuates circadian variability in breathing during sleep in mice but does not predispose to apnea.

Obesity is a primary risk factor for the development of obstructive sleep apnea in humans, but the impact of obesity on central sleep apnea is less clear. Given the comorbidities associated with obesity in humans, we developed techniques for long-term recording of diaphragmatic EMG activity and polysomnography in obese mice to assess breathing patterns during sleep and to determine the effect of obesity on apnea generation. We hypothesized that genetically obese ob/ob mice would exhibit less variability in breathing across the 24-h circadian cycle, be more prone to central apneas, and be more likely to exhibit patterns of increased diaphragm muscle activity consistent with obstructive apneas compared with lean mice.

The Effects of Sex and Chronic Restraint on Instrumental Learning in Rats.

Chronic stress has been shown to impact learning, but studies have been sparse or nonexistent examining sex or task differences. We examined the effects of sex and chronic stress on instrumental learning in adult rats. Rats were tested in an aversive paradigm with or without prior appetitive experience, and daily body weight data was collected as an index of stress.

Sleep-related epilepsy in a Long-Evans hooded rat model of depression.

Introduction: Neonatal treatment with clomipramine (CLI) has been shown to have reliable behavioral and biological changes that mimic major symptomatic and biochemical changes found in depression. This paper further explores a common feature of depression, the comorbidity of seizure activity and depressive behaviors in this mode.

Methods: Rat pups were neonatally treated with 40 mg/kg/day of CLI from postnatal day 8 through 21.

Chronic developmental exposure to phenytoin has long-term behavioral consequences.

Anti-epileptic compounds have been linked to several developmental disorders. Specifically, fetal exposure to phenytoin is linked to fetal hydantoin syndrome in humans. We have developed a rat model of fetal hydantoin syndrome in an effort to explore the relationship between drug exposure, development, and learning and memory.

Exploring human interaction and diet effects on the behavior of dogs in a public animal shelter.

This study examined the effects of 2 manipulations--a brief, regular period of human contact and diet--on the behavior of dogs confined in a public animal shelter. A behavioral battery designed to assess reactions to novel situations, and a test of responsiveness to an unfamiliar human were administered both prior to (pretest) and immediately following (posttest) the 8-week intervention period. Overall, the regular periods of increased human contact together with a diet that contained augmented levels of digestible protein, fat, calories, and animal-derived ingredients reduced signs of behavioral reactivity from pretest to posttest.

Effects of restricted spectral rearing on the development of zebrafish retinal physiology.

Research has shown that rearing in abnormal lighting environments affects both visual behavior and retinal physiology in zebrafish larvae. These studies, however, used only constant dark and constant white light as the experimental rearing conditions. This study assessed the effects of rearing larvae in restricted spectral lighting environments on zebrafish retinal physiology.

Visual processing of the zebrafish optic tectum before and after optic nerve damage.

Although the zebrafish has become an important model in visual neuroscience, little has been done to examine the processing of its higher visual centers. The purpose of this work was twofold. The first purpose was to examine the physiology of the zebrafish retinotectal system and its relationship to retinal physiology.

Effects of a program of human interaction and alterations in diet composition on activity of the hypothalamic-pituitary-adrenal axis in dogs housed in a public animal shelter.

Objective: To determine whether a program of human interaction or alterations in diet composition would alter activity of the hypothalamic-pituitary-adrenal (HPA) axis in dogs housed in an animal shelter.

Design: Prospective study.

Animals: 40 dogs.