title: Distribution and neurochemical features of neuronal nitric oxide synthase-expressing interneurons in the rat dentate gyrus.
abstract: Neuronal nitric oxide synthase (nNOS)-expressing interneurons are abundant in the dentate gyrus (DG) of rodents. In the present study, we immunohistochemically analyzed nNOS-positive cells in the rat DG by focusing on their GABAergicity, laminar distribution, and co-localization with calcium-binding proteins and neuropeptides. Experiments were conducted in adult male Sprague Dawley rats. Within the DG, nNOS-positive cells were found to reside in all three layers of DG; percentages of distribution in the molecular layer, granule cell layer and the hilus are 25.4%, 9.4% and 65.2%, respectively. Almost every nNOS-positive cell expressed glutamic acid decarboxylase 67 (GAD67) or glutamic acid decarboxylase 65 (GAD65). In the molecular layer, nearly two-thirds of GAD67-positive cells expressed nNOS. Percentages of nNOS-positive interneurons that expressed cholecystokinin, vasoactive intestinal polypeptide, parvalbumin, somatostatin, neuropeptide Y, and calretinin were approximately 0.8%, 1.8%, 9.2%, 10.3%, 13.8%, and 24.4%, respectively. In the molecular layer, the number of nNOS-positive cells far exceeded the sum total of cells positive for both nNOS and any of the above mentioned calcium-binding proteins or neuropeptides, indicating that a large proportion of nNOS-positive interneurons seldom express calcium-binding proteins or neuropeptides in this area. We conclude that nNOS expressing cells are an important neurochemically defined type of GABAergic interneuron in the rat DG showing a specific laminar-dependent distribution and expressing calcium-binding proteins and neuropeptides at different frequencies. In the molecular layer, most nNOS-positive interneurons do not express calcium-binding proteins or neuropeptides; they could be the missing pieces in the GABAergic interneuron jigsaw puzzle of this DG layer.
authors: Institute of Physiology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, China.
authors: Zhaoliang
authors: Z
authors: Liang
authors: Lin
authors: L
authors: Zhang
authors: Xiaochen
authors: X
authors: Wang
authors: Fei
authors: F
authors: Gao
authors: Xiaona
authors: X
authors: Wang
authors: Shuo
authors: S
authors: Zhou
authors: Shuyan
authors: S
authors: Yu
authors: Ren-Zhi
authors: RZ
authors: Zhan
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000918:Antibody Specificity; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002766:Cholecystokinin / Q000378:metabolism; D018891:Dentate Gyrus / Q000166:cytology*; D005968:Glutamate Decarboxylase / Q000378:metabolism; D007395:Interneurons / Q000201:enzymology*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009478:Neuropeptide Y / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D014660:Vasoactive Intestinal Peptide; D002766:Cholecystokinin; D052248:Nitric Oxide Synthase Type I; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; C401141:glutamate decarboxylase 2