Grant: Project Grant

The brainstem contains genetically programmed circuits for the expression of life-sustaining orofacial functions, such as breathing, suckling, licking, sniffing, and whisking in rodents. These behaviors meet the need of basic physiological functions such as breathing and nutrient ingestion. Orofacial activities also serve to explore the environment and communicate emotional states through facial expressions and vocalization. In rodents, vibrissa movement is an important component of orofacial activities. In the present proposal we seek to identify brain circuits that control vibrissa motion, and determine under which behavioral conditions these different circuits are recruited. Toward this goal, we use virus-based methods to trace neuronal circuits, and to activate or inactivate specific regions of the brain stem that are involved in the control of vibrissa motion. Electrophysiological recordings are also carried out in alert rats to correlate neuronal activities with vibrissa motion that are associated with exploratory activities or with emotional reactions. Despite the behavioral importance of facial expressions in social communications in man and mammals, the neurophysiological basis of these activities remains poorly understood. Our research program might open new perspectives on this aspect of animal and human behavior.