A comparison of GAD- and GABA-immunoreactive neurons in the first somatosensory area (SI) of the rat cortex.

Neurons immunoreactive for anti-glutamic acid decarboxylase (anti-GAD) and anti-gamma-aminobutyric acid (anti-GABA) were compared in adjacent sections from the rat somatosensory cortex (SI). GAD- and GABA-positive neurons in animals either treated or not treated with colchicine were found to occur at a ratio of 1:2. Measurement of areas of GAD- and GABA-immunoreactive neurons confirmed the presence of an 'exuberant' GABA-positive neuronal population not visualized by the GAD antiserum.