Effect of auditory cortical ablation on functioning of the doppler echolocation system in horseshoe bats

The effect of unilateral and bilateral partial and total ablation of the auditory cortex on compensation of Doppler frequency shifts in echosignals was studied in greater horseshoe bats moving in space. The ability of the bats to compensate Doppler surges in the echolocation signal was found to be worsened even after partial ablation of the auditory cortex. Total bilateral ablation led to more marked and irreversible changes in the functioning of the Doppler echolocation system. In this case the degree of compensation in the decorticated animals was only 33% of normal; the return of the frequency of the constant part of the signal to the resting level after movement of the animal ceased was delayed. After total ablation of the auditory cortical projection area definite retrograde degeneration of cells of the medial geniculate body was observed. It is concluded from the results that the auditory cortex in bats plays a direct part in echolocation spatial analysis.