Analysis of the superior colliculus auditory space map function in guinea pig behavior

Abstract

In the deep layers of the superior colliculus (SC) a map-like representation of auditory space and multimodal integration has been described, but the contribution of the map to guinea pig behavior is unknown. The present work was targeted at exploring its possible role in both spatial auditory discrimination learning and in a positive patterning paradigm, where combined visual/auditory stimuli were rewarded. Emergence of the auditory map was prevented by a dark-rearing regime known to cause a selective disturbance of this map. Surprisingly, dark-reared guinea pigs were able to learn both the spatial auditory task and the positive pattern paradigm showing no deficit compared to age-matched controls. Subsequent electrophysiological mapping confirmed the lack of the auditory space map in deprived animals but not in controls. Accordingly, our data suggest that the SC map of auditory space is not essential for learning the behavioral paradigms used. The possible contribution of other auditory/multimodal brain areas is discussed.