title: Cytoarchitecture of nitrergic neurons in the human striatum and subthalamic nucleus.
abstract: Nitric oxide (NO) is a gaseous molecule that modulates several physiological processes, including signal transmission in the central nervous system. There is evidence supporting NO as a major neurotransmitter involved in motor and emotion/behavior control. We investigated the distribution and morphology of nitrergic neurons in the two main input structures of the basal ganglia of human brain: the striatum and subthalamic nucleus.
  
  
  
  We studied samples of striatum (caudate and putamen) and subthalamic nucleus of 20 human brains from subjects without neurological/psychiatric diseases. The tissues were stained by histochemistry for nicotinamide adenine dinucleotide phosphate diaphorase activity and by immunohistochemistry for neuronal NO synthase (nNOS). Subsequently, we analyzed the nitrergic neuronal profile and its morphometric parameters.
  
  
  
  Our data corroborate that approximately 2% of neurons in striatum express nNOS and these exhibited morphology characteristic of interneurons. Posterior regions of the striatum have a higher nitrergic neuronal profile than anterior regions of this nucleus suggesting an anteroposterior gradient of nitrergic neurons. Posterior limbic-associated areas of the striatum have a higher nitrergic neuronal profile compared to other functional subdivisions. Also, approximately 90% of neurons in the subthalamic nucleus express nNOS.
  
  
  
  A remarkable presence of nitrergic neurons in the human striatum and subthalamic nucleus suggests that NO may play a critical role in the physiology of these nuclei.
authors.affiliation: Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Research Support on Applied Neuroscience (NAPNA-USP), Brazil. Electronic address: bruls4@usp.br.
authors.forename: Bruno Lopes Dos
authors.initials: BL
authors.lastname: Santos-Lobato
authors.affiliation: Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil; Department of Morphology, Physiology and Basic Pathology, Ribeirão Preto Dentistry School, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Research Support on Applied Neuroscience (NAPNA-USP), Brazil. Electronic address: eadelbel@forp.usp.br.
authors.forename: Elaine
authors.initials: E
authors.lastname: Del-Bel
authors.affiliation: Department of Pathology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil. Electronic address: pittella@medicina.ufmg.br.
authors.forename: José Eymard Homem
authors.initials: JE
authors.lastname: Pittella
authors.affiliation: Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Research Support on Applied Neuroscience (NAPNA-USP), Brazil. Electronic address: tumasv@rnp.fmrp.usp.br.
authors.forename: Vitor
authors.initials: V
authors.lastname: Tumas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001344:Autopsy; D003342:Corpus Striatum / Q000166:cytology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009252:NADPH Dehydrogenase / Q000378:metabolism; D026602:Nitrergic Neurons / Q000166:cytology* / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism; D010751:Phosphopyruvate Hydratase; D020531:Subthalamic Nucleus / Q000166:cytology*
chemical_list: D052248:Nitric Oxide Synthase Type I; D009252:NADPH Dehydrogenase; D010751:Phosphopyruvate Hydratase
keywords: Basal ganglia; Human brain; Nitric oxide; Striatum; Subthalamic nucleus