By using a combined closed and free-field stimulation system, binaurality and azimuth tuning of the neurons in the auditory cortex of the big brown bat, Epte-sicus fuscus, were studied. A variety of azimuth-tuning fun...By using a combined closed and free-field stimulation system, binaurality and azimuth tuning of the neurons in the auditory cortex of the big brown bat, Epte-sicus fuscus, were studied. A variety of azimuth-tuning functions were demonstrated for the binaural neurons. The large majority of EE (contralateral and ipsilateral excitatory) neurons exhibited azimuth selectivity with the best azimuths (BA) at contralateral 30°-40°, some at ipsilateral 20°-40° and preferred azimuth ranges (PAR, response amplitude 】75% of maximum) between 8° and 40°. Sound source azimuths strongly modulate spike counts with a mean modulation depth of 83.8% for EE neurons. EI (contralateral excitatory and ipsilateral inhibitory) neurons have simple azimuth tuning with BA located at contralateral 20°-40° and a broad PAR ranged from 30° to 55°. The present results suggest that azimuth-tuning characteristics of binaural neurons in the auditory cortex of the bat are of significance for acoustic behaviour.展开更多
基金This work was conducted in the laboratory of P. Jen of University of Missouri-Columbia MO and was supported by a grant from the Human Frontier Science Program The preparation of this manuscript is supported by the National Natural Science Foundation
文摘By using a combined closed and free-field stimulation system, binaurality and azimuth tuning of the neurons in the auditory cortex of the big brown bat, Epte-sicus fuscus, were studied. A variety of azimuth-tuning functions were demonstrated for the binaural neurons. The large majority of EE (contralateral and ipsilateral excitatory) neurons exhibited azimuth selectivity with the best azimuths (BA) at contralateral 30°-40°, some at ipsilateral 20°-40° and preferred azimuth ranges (PAR, response amplitude 】75% of maximum) between 8° and 40°. Sound source azimuths strongly modulate spike counts with a mean modulation depth of 83.8% for EE neurons. EI (contralateral excitatory and ipsilateral inhibitory) neurons have simple azimuth tuning with BA located at contralateral 20°-40° and a broad PAR ranged from 30° to 55°. The present results suggest that azimuth-tuning characteristics of binaural neurons in the auditory cortex of the bat are of significance for acoustic behaviour.
