Previous studies, using a biochemical measure of serotonergic neuronal function, show that inescapable, randomly presented sound pulses activate serotonergic neurons in the @entity35 median raphe but not dorsal raphe nucleus. The present study reveals that this activation also occurs in @entity750 projection areas, in hippocampus, nucleus accumbens and cortex but not in caudate nucleus. The selectivity of this response is examined by comparing the response to sound stress with that produced by @entity1286 , a treatment known to selectively activate dorsal raphe but not median raphe serotonergic neurons. Two approaches are used in @entity35 to measure the activation of serotonergic neurons: (1) determination ex vivo of accumulation of @entity2476 ( @entity2476 ) in tissue from the dorsal and median raphe nuclei, hippocampus, cortex, caudate nucleus, and nucleus accumbens following in vivo inhibition of aromatic @entity535 decarboxylase; and (2) measurement of extracellular @entity750 levels in hippocampus, caudate nucleus, and nucleus accumbens. Sound stress increases @entity2476 accumulation in median raphe nucleus, hippocampus, cortex, and nucleus accumbens, but not dorsal raphe nucleus or caudate nucleus. Sound stress also enhances extracellular @entity750 levels in hippocampus and nucleus accumbens, but not caudate nucleus. In contrast, the @entity1286 treatment enhances @entity2476 accumulation in dorsal raphe nucleus, cortex and caudate nucleus, but not in median raphe nucleus, hippocampus or nucleus accumbens. Furthermore, it increases extracellular @entity750 levels in only the caudate nucleus. The combined effects of sound stress and @entity1286 on @entity2476 accumulation are identical to those obtained by each treatment individually. These findings provide further support for the presence of serotonergic neurons within the median raphe nucleus that have a unique response profile. These neurons may have an important role in responses or adaptations to stress.

Further studies on the activation of XXXX median raphe serotonergic neurons by inescapable sound stress.

@entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino acid'] @entity2476 :: ('CHEBI:28171', 'Chemical') :: ['5-hydroxytryptophan', '5-HTP'] @entity1286 :: ('MESH:D009020', 'Chemical') :: ['morphine'] @entity750 :: ('MESH:D012701', 'Chemical') :: ['serotonin'] @entity35 :: ('10116', 'Species') :: ['rat', 'Sprague-Dawley rat']
@entity35 :: (10116,Species) :: ['rat']
