Structural Organization of the Barrel Cortex in Rats (an immunohistochemical study)

Abstract

Immunohistochemical studies of the spatial distribution of neuronal and glial elements in barrels of the somatic cortex of the rat (n = 10) are reported. High levels of synaptophysin expression were detected in barrel walls, and groupings of astroglial cells were seen in their central parts. Electron microscopic studies of chemical synapses demonstrated a predominance of asymmetrical perforated axospinous contacts, which are presumptively excitatory. Symmetrical inhibitory synapses were seen more frequently in barrel walls, where neuron bodies were more densely distributed, as well as on large dendrite processes. The numbers of vertically orientated myelinated axons in barrels were significantly greater than the numbers of horizontally located connections between neurons.