The effects of environmental enrichment and social isolation and their reversion on anxiety and fear conditioning.

Animal models of fear and anxiety provide important insight into anxiety-related symptoms in humans. Environmental physical conditions and social contact influence behavior and brain plasticity particularly at early developmental stages and have long lasting effects reaching even adulthood. The potential benefit that a later environmental enrichment may have on rats raised in isolation is however not fully understood.

Age-dependent effects of environmental enrichment on spatial memory and neurochemistry.

Although aging and environmental stimulation are well-known to affect cognitive abilities, the question of whether aging effects can be distinguished in already-mature adult rats has not been fully addressed. In the present study, therefore, young and mature adult rats were housed in either enriched or standard conditions (EE or SC) for three months. Open-field (OFT) and radial-maze (RM) behavior, and ex-vivo contents of GABA and glutamate in hippocampus, and of dopamine and DOPAC in ventral striatum (VS) were analyzed and compared between the four groups.

Individual differences in the forced swimming test and neurochemical kinetics in the rat brain.

Individual differences in the forced swimming test (FST) could be associated with differential temporal dynamics of gene expression and neurotransmitter activity. We tested juvenile male rats in the FST and classified the animals into those with low and high immobility according to the amount of immobility time recorded in FST. These groups and a control group which did not undergo the FST were sacrificed either 1, 6 or 24 h after the test.

Individual differences in the immobility behavior in juvenile and adult rats are associated with monoaminergic neurotransmission and with the expression of corticotropin-releasing factor receptor 1 in the nucleus accumbens.

The study of individual differences provides an important methodological approach to analyze the neurobehavioral spectrum of a given cohort in order to understand brain function and disease. Based on immobility time in the forced swimming test (FST) juvenile and adult rats were classified as subgroups with low and high immobility. Afterwards, we compared behavior, neurochemical parameters, and gene expression profiles in some brain areas of rats with low and high immobility only.

Behavioral and neurochemical characterization of maternal care effects on juvenile Sprague-Dawley rats.

Maternal care represents a major constituent of early life environment and has the potential to modulate critical neurobehavioral responses to stress. The aim of the present study was to determine the effects of naturally occurring variations in maternal care on behavioral and neurochemical responses of juvenile Sprague-Dawley rats. A group of dams were classified based on their licking behavior in high and low licking-grooming mothers.

Maternal behavior as an early modulator of neurobehavioral offspring responses by Sprague-Dawley rats.

Maternal care plays an important role as an early modeler of neurodevelopment and brain function, and its effects remain until adulthood. Such modeling or programming has shown to influence the stress response and represents a key susceptibility factor in the development of mood disorders. In order to characterize such process which is still not clear, male offspring were classified in animals with low, medium and high licking/grooming (LG) according to the maternal behavior.