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Distribution and proportions of GABA‐Immunoreactive neurons in cat primary somatosensory cortex
Author(s) -
Li Jianying,
Schwark Harris D.
Publication year - 1994
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903430302
Subject(s) - bicuculline , somatosensory system , gabaergic , neuroscience , receptive field , neuron , biology , inhibitory postsynaptic potential , gabaa receptor , laminar flow , gamma aminobutyric acid , receptor , physics , biochemistry , thermodynamics
Certain receptive field properties of cortical neurons depend upon inhibitory, GABAergic inputs. In the somatosensory cortex, iontophoresis of bicuculline, a GABA A receptor blocker, results in enlargement of receptive fields. However, bicuculline's effectiveness in changing receptive field size varies with the neuron's adaptation characteristics, location within a particular submodality region, and laminar location. To test whether regional differences in the effectiveness of bicuculline are correlated with the distribution of cortical GABAergic neurons, we determined the number and proportion of GABA‐immunoreactive [GABA(+)] neuron, within cat primary somatosensory cortex. The laminar distribution of GABA(+) neurons was similar across all four cytoarchitechonic areas of primary somatosensory cortex, with layer II containing the highest areal density of GABA(+) neurons. Numerical proportions of GABA(+) neurons in the total neuron population were similar in areas 3b and 2 (29.8% and 22.6%, respectively). Laminar distributions of the proportions of GABA(+) neurons were also similar in these two areas; in both areas layer I contained the highest proportion of GABA(+) neurons. The laminar distribution of GABA(+) neuron density as well as GABA(+) neuron proportion differed from the reported laminar distribution of bicuculline effects on respective field size. Moreover, within area 3b, these measures showed no evident pattern that might correspond to rapidly adaptation and slowly adapting submodality regions. © 1994 Wiley‐Liss, Inc.