Meeting Abstract
Sensory self-stimulation from an animal’s own behavior often produces stronger signals than important stimuli in its environment, yet the brain filters out these self-generated signals. We have previously shown that the principal neurons in the primary electrosensory nucleus of the skate (Leucoraja erinacea) learn to recognize and reject sensory signals consistently associated with the animal’s own behavior or the motor commands for behavior recorded in a paralyzed fish. This adaptive filter mechanism is mediated by a distinctive anatomical organization and molecular layer that is also characteristic of the cerebellum. The same organization is found in the medial nucleus, which processes incoming mechanosensory lateral line information. This similarity suggests the medial nucleus may contain the same adaptive filter mechanism to filter out mechanosensory self-stimulation. Previous work of Perks (2007) demonstrates the presence of adaptive filtering in the lateral line when an external mechanosensory stimulus is consistently linked with ventilation or fictive ventilation. Here we provide additional support for Perks’ findings, as well as results indicating adaptive filtering in cells that were tested by associating a stimulus with fictive swimming, another distinct behavior. For these experiments we coupled an external mechanosensory stimulus to each cycle of the skate’s fictive swimming as indicated by motor discharges recorded from the spinal cord. These results showing the presence of the adaptive filter in yet another sensory system help piece together a model of how the cerebellum integrates, processes, and predicts sensory consequences of behavior.
