Hearing involves several centers, called nuclei, located in the brainstem, where auditory information is processed before being passed on to the midbrain and higher centers. For many auditory signals, aspects of timing are very important. Complex sounds, for example, often have a periodicity in their waveform that may be heard as a particular pitch, or frequency. Anatomical studies suggest that one of the brainstem nuclei, called the ventral nucleus of the lateral lemniscus or VNLL, receives a large input from the one ear on the opposite side, from cell types that specifically transmit the temporal pattern of a sound. This project uses a novel awake preparation for physiological recordings of nerve cells in the VNLL, to test whether the VNLL itself shows an orderly mapping of responses to pitch periodicity. Results will be important because the VNLL has been so understudied in any mammals except for echolocating bats. The impact of this work will be important to understanding the role of this major nucleus in temporal pattern processing, and will also be important to help understand pitch-periodicity perception in humans, which in turn can be important in speech recognition, and could lead to improved electronics for speech processors and artificial intelligence (AI) networks.
