1. A weakening of inhibitory intercortical influences using microelectrophoretic applications of picrotoxin and bicucillin results in a lowering or complete elimination of the directional sensitivity of the neurons of the vibrissae projection area. 2. Activation of inhibitory processes evoked by chemical microstimulations (application of glutamate) is accompanied by a manifestation of directional sensitivity in neurons originally not possessing this property and is also accompanied by changes in existing detector characteristics for initially directionally sensitive cells. 3. Inhibitory influences arising during the activation of spatially separated microregions of cortex shape the directional sensitivity in neurons of the vibrissae projection area with clearly differing directions of preferential reaction. 4. The inhibitory processes evoked by natural afferent stimulations modify the detector characteristics of the neurons, causing a manifestation of directional sensitivity in cells which previously did not possess them.