The overall goal of the proposed research is to investigate pre-motor and sensory neural activity in an organism actively exploring its environment. The echolocating bat will serve as a model system for the proposed research. Echolocation is a highly developed behavior that coordinates the production of sonar vocalizations, head and pinna movements, with analysis of returning echoes that carry information about reflecting objects. Therefore, the generation of orienting behaviors, including vocalizations, directly influences the sensory information used to build a representation of the auditory environment. We propose to investigate audio-motor integration in the superior colliculus (SC), a midbrain structure implicated in sensor/motor integration. Current pilot studies show brisk neuronal activity in the superior colliculus preceding and following the production of sonar vocalizations in a time-locked fashion.This is in contrast to the relatively sluggish sensory responses observed in recordings from passively listening bats. This research will: 1) investigate the timing and pattern of neuronal activity in the superior colliculus prior to and during head and pinna orienting movements, 2) investigate the timing and pattern of neuronal activity in the superior colliculus related to sonar vocal production, and 3) compare the responses of combination-sensitive (echo-delay tuned) neurons between actively echolocating and passively listening conditions.
