title: Quantitative analysis of neurons and glial cells in the rat somatosensory cortex, with special reference to GABAergic neurons and parvalbumin-containing neurons.
abstract: The number of neuronal and glial cells in the rat somatosensory cortex (barrel area) has been estimated by a stereological method, the disector, using pairs of toluidine blue-stained, plastic-embedded 0.5-microns-thick sections, 1.5 microns distant from each other. Chemical properties of those disector-counted cells were further analyzed by postembedding immunocytochemical methods on adjacent semithin sections. Thus we were able to analyze quantitatively number, distribution, and proportion of five cell types: (1) gamma-aminobutyric acid-(GABA)-negative neurons; (2) GABA-like immunoreactive (GABA-LIR) neurons; (3) a specific calcium-binding protein parvalbumin-immunoreactive (PV-IR) neurons, a subpopulation of GABA-LIR neurons; (4) S-100 beta-LIR glial cells (astrocytes); and (5) S-100 beta-negative glial cells (oligodendrocytes and microglia). The densities of total cells, glial cells, and neurons in the rat somatosensory cortex were 85.4 +/- 10(3)/mm3, 30.5 x 10(3)/mm3, and 54.9 x 10(3)/mm3, respectively. Of all neurons 25% and 14% were GABA-LIR and PV-IR, respectively; all PV-IR neurons are GABA-LIR, and thus about 54% of GABA-LIR neurons are PV-positive. The number of total cells under a unit surface area of 1 mm2 through the thickness of the somatosensory cortex was 171.6 x 10(3); the number of neurons and glial cells were 110.2 x 10(3) and 61.4 x 10(3), respectively. There were 27.7 x 10(3) GABA-LIR neurons and 15.0 x 10(3) and 12.7 x 10(3) PV-IR neurons and PV-negative GABA-LIR neurons, respectively. The laminar distribution of each group of cells shows prominent differences, indicating that the cellular composition was different from layer to layer. The density of GABA-LIR neurons was highest in layer IV. The numerical density of PV-IR neurons was 2-4 times higher in layer IV than in layers II/III, V, and VI, whereas that of PV-negative GABA-LIR neurons was almost constant throughout the layers.
authors: Department of Anatomy and Neurobiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors: J Q
authors: JQ
authors: Ren
authors: Y
authors: Y
authors: Aika
authors: C W
authors: CW
authors: Heizmann
authors: T
authors: T
authors: Kosaka
mesh_terms: D000818:Animals; D048588:Benzoxazines; D007150:Immunohistochemistry; D008297:Male; D009457:Neuroglia / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010078:Oxazines; D010320:Parvalbumins / Q000276:immunology / Q000378:metabolism*; D016613:Plastic Embedding; D051381:Rats; D017208:Rats, Wistar; D013003:Somatosensory Cortex / Q000166:cytology / Q000502:physiology*; D014048:Tolonium Chloride; D005680:gamma-Aminobutyric Acid / Q000276:immunology / Q000502:physiology*
chemical_list: D048588:Benzoxazines; D010078:Oxazines; D010320:Parvalbumins; D014048:Tolonium Chloride; C028911:cresyl violet; D005680:gamma-Aminobutyric Acid