Psychoneuroendocrinology
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Psychoneuroendocrinology · Oct 2009
Comparative StudyEnduring effects of environmental enrichment from weaning to adulthood on pituitary-adrenal function, pre-pulse inhibition and learning in male and female rats.
Environmental enrichment (EE) increases stimulation and provides richer sensory, cognitive and motor opportunities through the interaction with the social and physical environment. EE produces a wide range of neuroanatomical, neurochemical and behavioural effects in several animal species. However, the effects of EE have mainly been studied shortly after the treatment, so its long-lasting effects remain to be elucidated. ⋯ EE increased social exploratory behaviour towards juvenile rats and social discrimination in males, but decreased social discrimination in females. Finally, in the Hebb-Williams maze, rats reared in EE showed better performance in terms of reduced number of errors and shorter distances travelled in the mazes. It is concluded that EE exposure from weaning to adulthood has important and long-lasting consequences on physiological and behavioural variables, most of them similar in both sexes, although sex differences in response to the EE are also reported.
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Psychoneuroendocrinology · Oct 2009
The BDNF Val66Met polymorphism: relation to familiar risk of affective disorder, BDNF levels and salivary cortisol.
Brain-derived neurotrophic factor (BDNF) and the hypothalamic-pituitary-adrenal (HPA) axis are considered to play an important role in the pathophysiology of affective disorders. The aim of the present study was to investigate whether the BDNF Val66Met polymorphism is associated with a familiar risk of affective disorder and whether these genotypes affect whole blood BDNF level and salivary cortisol. ⋯ Individuals at high risk of affective disorders and who are carriers of the met allele of the Val66Met polymorphism may present with an enhanced stress response. The presence of a specific genotype alone may not enhance the risk of developing an affective episode. Rather, the altered stress response may be expressed only in combination with other risk variants through interactions with the environment.
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Psychoneuroendocrinology · Oct 2009
Endogenous noradrenergic activation and memory for emotional material in men and women.
A plethora of evidence from the animal and human literature suggests that emotionally arousing material is often remembered better than is neutral material, and that this effect critically involves noradrenergic activation during and soon after exposure to the emotional material. A crucial prediction of this hypothesis is that endogenous adrenergic activation should relate positively and selectively to memory for emotional events in humans. Salivary alpha-amylase (sAA), a biomarker for adrenergic activity was measured in response to viewing a series of mixed emotional and neutral images to test this prediction in healthy men and women. ⋯ The results support the view that adrenergic activation underlies enhanced memory for emotional material in humans, namely, that endogenous adrenergic activation in response to an emotional event should predict long-term memory for the event. The selectivity of the relationship for emotional, and not neutral, material supports the view derived from earlier research that stress activation does not necessarily enhance memory for all aspects of an emotional event; rather, that it acts disproportionately to influence memory for the more emotional aspects of an event. These findings are the first involving human subjects to indicate that the degree of endogenous noradrenergic activation in response to emotionally arousing stimuli predicts the strength of long-term memory for those stimuli.