CATECHOLAMINE-CRF SYNAPTIC INTERACTION IN A SEPTAL BED NUCLEUS - AFFERENTS OF NEURONS IN THE BED NUCLEUS OF THE STRIA TERMINALIS

Projections of catecholamine neurons to the bed nucleus of the stria t erminalis (BST), especially its corticotropin releasing factor (CRF)-p roducing neurons, are implicated as being major contributors to the ne urochemically mediated central regulation of the stress response. The purpose of the present study was to examine in the BST of the rat brai n the morphological characteristics of interactions between two neuron populations of the brain, catecholaminergic and CRF neurons. A double -label immunocytochemical, light and electron microscopic technique al lowed the demonstration of the synaptic interaction between dopamine ( DA, i.e, tyrosine hydroxylase-containing) and norepinephrine (NE, i.e. , dopamine-beta-hydroxylase-containing) axons and CRF neurons in the B ST. DA terminals formed synapses with dendrites and soma of CRF neuron s in the dorsolateral BST. NE terminals formed synapses with dendrites of CRF neurons in the ventrolateral BST. In conclusion, catecholamine afferents can directly affect the contribution of CRF neurons of the BST to an animals response to stress.