[The characteristics of the synaptic apparatus of the primary auditory area (A1) of the cat cerebral cortex].

Quantitative and qualitative comparative studies of the synaptic apparatus in different layers of the primary auditory cortex (AI) in cat were performed using an electron microscope. The total average density of axonal terminal profiles in this area was 255 terminals per 1000 microns2 of the slice area. These profiles occupied 8.9% of the total studied area of slices. 45.3% of axonal terminals in area AI formed synapses on spines, 48.5%--on dendrites and 6.2%--on neuronal somata. 83.9% of synapses were asymmetric, 16.1%--symmetric. The number of synapses in 1 mm3 of the neural tissue in area AI estimated by stereological methods was 322.8 x 10(6).