Differential Histone Acetylation in Sub-Regions of Bed Nucleus of the Stria Terminalis Underlies Fear Consolidation and Extinction

OBJECTIVE: The hallmark of anxiety disorders is excessive fear. Previous studies have suggested that selective neural projections from Basal nucleus of stria terminalis (BNST) to amygdala and vice-versa precisely control the fear learning process. However the exact mechanism how the BNST controls fear consolidation and its extinction is largely unknown. In the present study we observed the changes in the BNST sub-regions following fear conditioning and its extinction. METHODS: The change in the number of positive neurons was determined by immunohistochemistry for Acetyl H3 (Histone 3), Acetyl H4 (Histone 4), cAMP response element binding Protein (CBP) and c-fos in three sub-regions of the BNST namely the anterio-lateral BNST (STLP) and anterio-medial BNST (STMA), and lateral-ventral BNST (STLV) of rats subjected to auditory fear conditioning and extinction. RESULTS: We found significant increase in the number of CBP, acetyl H3 and acetyl H4 positive neurons in the STMA and STLV but not in the STLP after fear conditioning. However, following fear extinction the number of CBP, acetyl H3 and acetyl H4 positive neurons increased significantly in the STLP but not in the STMA and STLV. Similar changes were observed in the number of c-fos positive neurons after fear consolidation and extinction. CONCLUSION: The results from this study suggest that the differential histone acetylation in the different sub-regions of the BNST following fear learning and its extinction may be responsible for changes in the neuronal activation patterns resulting in either fear or less fear.

Melanocortin 4 Receptor and Dopamine D2 Receptor Expression in Brain Areas Involved in Food Intake

BACKGROUND: The melanocortin 4 receptor (MC4R) is involved in the regulation of homeostatic energy balance by the hypothalamus. Recent reports showed that MC4R can also control the motivation for food in association with a brain reward system, such as dopamine. We investigated the expression levels of MC4R and the dopamine D2 receptor (D2R), which is known to be related to food rewards, in both the hypothalamus and brain regions involved in food rewards. METHODS: We examined the expression levels of D2R and MC4R by dual immunofluorescence histochemistry in hypothalamic regions and in the bed nucleus of the stria terminalis (BNST), the central amygdala, and the ventral tegmental area of transgenic mice expressing enhanced green fluorescent protein under the control of the D2R gene. RESULTS: In the hypothalamic area, significant coexpression of MC4R and D2R was observed in the arcuate nucleus. We observed a significant coexpression of D2R and MC4R in the BNST, which has been suggested to be an important site for food reward. CONCLUSION: We suggest that MC4R and D2R function in the hypothalamus for control of energy homeostasis and that within the brain regions related with rewards, such as the BNST, the melanocortin system works synergistically with dopamine for the integration of food motivation in the control of feeding behaviors.

THE CONNECTION AMONG THE MARGINAL DIVISION OF STRIATUM,AMYGDALOID NUCLEUS AND BED NUCLEUS OF THE STRIA TERMINALIS IN THE RAT BRAIN AS REVEALED BY IMMUNOHISTOCHEMISTRY / 神经解剖学杂志

To understand the relationship of neurotransmitter between the striatum and limbic system such as amygdaloid nucle-us and bed nucleus of the stria terminalis. 30 male Sprague Dawley rats were used. Immunohistochemical ABC method was per-formed to detect the expression of substance P (SP), calcitonin gene-related peptide (CGRP), leucine-enkephalin (L-enk),cholecyctokinin (CCK) and neuronal nitric oxide synthase (NOS) on seetions of the brain. Some transmitters including substanceP, calcitonin gene-related peptide and cholecyctokinin were mainly distributed at the marginal division of the striatum. Theleucine-enkephalin was mainly distributed at the globus pallidus and was secondly distributed at the marginal division of the stria-tun. The neuronal nitric oxide synthase was mainly distributed at caudate putamen and the marginal division. All these transmit-ters were not only distributed at amygdaloid nucleus and bed nucleus of the stria terminalis, but also had fibers connection amongthe amygdaloid nucleus, marginal division and bed nucleus of the stria terminalis. CONCLUSION: There were special fibersconnection between the marginal division and other basal ganglia nucleus or the limbic system. The marginal division may beplayed some important functions of basal ganglia and limbic system.

DISTRIBUTION OF VASOACTIVE INTESTINAL POLYPEPTIDE-LIKE IMMUNOREACTIVITY IN THE BED NUCLEI OF THE STRIA TERMINALIS IN THE RAT / 解剖学报

Based on recent cellular architectural studies on the bed nuclei of the stria terminalis (BST) in the rat by Ju et al, we studied vasoactive intestinal polypeptidelike immunoreactivity (VIP-LI) in the BST using PAP and ABC techniques. (1) Compared with VIP-LI cells, the VIP-LI terminals were more abundant and concentrated. At the periphery of the oval nucleus and in the juxtacapsular nucleus, there was a dense accumulation of VIP-LI terminals. Less densely innervated areas were the part above the anterior commissure in the anterior lateral area and the central part of oval nucleus. The fusiform nucleus and rostral part of the anterior ventral area contained moderate amount of VIP-LI terminals. The principal nucleus, interfasicular nucleus, posterior dorsal nucleus and dorsal nucleus, were devoid of VIP immunoreactivity. VIP-LI fiber branches were sometimes seen going along the vessels in the BST. (2) VIP-LI cells were usually distributed in areas where the terminals were relatively sparse. In the central part of the oval nucleus, the VIP-LI cells were most concentrated, though the total number of it was less than that in the caudal part of the anterior dosal area, They were usually small fusiform in shape, however some were trangular or multipolar.