[Interaction of the somatosensory and auditory systems in awake cats at the level of the cortical projection zones]. / Vzaimodeistvie somatosensornykh i slukhovykh sistem u bodrstvuiushchikh koshek na urovne korkovykh proektsionnykh zon.

A comparative study of somato-acoustic interactions has been brought out by EP method in the auditory area A1 several projection areas of S1 and in S2 of non-immobilized cats with chronically implanted electrodes. Single cutaneous stimulation of the contralateral fore-leg with an intensity equal to 1.5 to 3 thresholds of EP appearance elicits in S1 and A1 three types of EPs differing in latencies and number of components. Preliminary rhythmic somatic stimulation has a predominantly facilitating effect on EPs appearing in response to tonal stimuli in the areas A1, S2, S1. Optimal conditions for facilitatory influences involve intervals of 250 to 500 msec, frequencies of somatic stimulation of 3 to 10 c/s and its intensity which does not elicit animal's motor reaction.

[Intercortical connections between the auditory fields and the motor area]. / Interkortikal'nye sviazi slukhovykh polei s motornoi oblast'iu.

The connections of auditory fields AI, AII and Ep with the motor area were studied in 14 cats by anterograde degeneration method by means of impregnation techniques of Nauta-Gigax and Fink-Heimer in Victorov's modification. Direct connections were established between the three auditory fields and the motor projection field of the forepaw. The connections coming from the auditory field Ep spread wider, to the motor projection field of the head. The greatest number of these interzonal connections originates in zone Ep, and the smallest in AII zone.

[Dynamics of evoked potentials at different points in the cat somatosensory cortex during elaboration of conditioned reflexes]. / Dinamika vyzvannykh potentsialov v razlichnykh punktakh somatosensornoi kory koshki pri stanovlenii uslovnykh refleksov.

In chronic experiments on cats a study was made of the spreading of evoked potentials (EP) in the somatosensory zones S1 and S2 in response to biologically significant tonal stimuli. The formation of conditioned connections enhances the capacity for polysensory reactions in different cortical somatic fields outside the zones of local projection of the unconditioned stimulus. As stable conditioned connections are formed, this capacity diminishes in relation to reinforced and, particularly, easily differentiated sounds: EP are more localized in response to the former, and disappear altogether when the latter are presented. The wide EP spreading in zones S1 and S2 is the longest in response to medium and fine differentiation tones, which points to the involvement of these zones in the integrative analysis of signals by their biological quality.