Effects of different kinds of acute stress on nerve growth factor content in rat brain.

Nerve growth factor (NGF) has several effects on the central nervous system; on the one hand NGF fosters survival and function of cholinergic neurons of the basal forebrain, on the other hand this protein is implicated in the stress response of the hypothalamic-pituitary-adrenocortical axis (HPAA). In this study we tested the influence of threatening and painful stress treatments in three different intensities as well as forced motoric activity on NGF content in different brain areas in adult rats. We found that threatening treatment with or without painful stimuli was followed by a significant decrease of NGF concentration in the amygdala (44.5%; P=0.03) and the frontal cortex (-45.5%; P=0.02). We also observed that after stress of forced motoric activity NGF content in the frontal cortex (-32%; P=0.01) and the hippocampus (-32%; P=0.006) was significantly reduced. Thus, NGF content in distinct brain regions is decreased, following different forms of acute stress. This might be relevant for the pathophysiological understanding of psychiatric diseases, such as depression, which are associated with stress.