A morphometric study of the progressive changes on NADPH diaphorase activity in the developing rat's barrel field.
The distribution of NADPH diaphorase (NADPH-d)/nitric oxide synthase (NOS) neurons was evaluated during the postnatal development of the primary somatosensory cortex (SI) of the rat. Both cell counts and area measurements of barrel fields were carried out throughout cortical maturation. In addition, NADPH-d and cytochrome oxidase (CO) activities were also compared in both coronal and tangential sections of rat SI between postnatal days (P) 10 and 90. Throughout this period, the neuropil distributions of both enzymes presented a remarkable similarity and have not changed noticeably. Their distribution pattern show the PMBSF as a two-compartmented structure, displaying a highly reactive region (barrel hollows) flanked by less reactive regions (barrel septa). The number of NADPH-d neurons increased significantly in the barrel fields between P10 and P23, with peak at P23. The dendritic arborization of NADPH-d neurons became more elaborated during barrel development. In all ages evaluated, the number of NADPH-d cells was always higher in septa than in the barrel hollows. Both high neuropil reactivity and differential distribution of NADPH-d neurons during SI development suggest a role for nitric oxide throughout barrel field maturation.
Laboratory of Functional Neuroanatomy, Department of Morphology, Federal University of Pará, 66075-900 Belém, PA, Brazil.
Marco Aurélio M
MA
Freire
Walace
W
Gomes-Leal
Walther A
WA
Carvalho
Joanilson S
JS
Guimarães
João G
JG
Franca
Cristovam W
CW
Picanço-Diniz
Antonio
A
Pereira
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002452:Cell Count; D002454:Cell Differentiation / Q000502:physiology; D048429:Cell Size / Q000502:physiology; D003712:Dendrites / Q000201:enzymology / Q000648:ultrastructure; D003576:Electron Transport Complex IV / Q000378:metabolism; D009252:NADPH Dehydrogenase / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D019581:Neuropil / Q000166:cytology / Q000201:enzymology; D026602:Nitrergic Neurons / Q000166:cytology / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013003:Somatosensory Cortex / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development*; D015854:Up-Regulation / Q000502:physiology; D014738:Vibrissae / Q000294:innervation / Q000502:physiology
D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase; D003576:Electron Transport Complex IV