"Animals actively acquire sensory information. Incoming sensory signals must therefore be processed in the context of self-generated motor commands in order to generate useful sensory percepts. Equally, sensory information is an essential guide during movement. The neuronal circuits and synaptic mechanisms underlying sensorimotor integration in the mammalian brain are currently poorly understood.The mouse whisker sensorimotor system is developing into a useful model for studying active sensory perception offering the possibility for causal and mechanistic insight into the molecular, synaptic, cellular and network functions underlying simple sensorimotor behaviors. Utilizing cutting edge technology, here I propose a concerted experimental research program, which will provide data on fundamental aspects of cortical function during active whisker sensory perception:1. Functional mapping of the mouse sensorimotor cortex through combination of optogenetics to control cortical activity and optical imaging to measure the spatiotemporal dynamics of cortical activity in awake mice during execution of object localisation and texture discrimination tasks.2. Two-photon targeted whole-cell recordings and optogenetic manipulation will be used to explore the role of specific classes of excitatory neocortical neurons with identified long-range axonal projections during execution of object localisation and texture discrimination tasks.3. The roles of genetically-defined classes of neocortical GABAergic neurons during these whisker-dependent tasks will be explored through combination of optogenetics and two-photon targeted whole-cell recordings.Together these investigations will define key organising principles for the functional operation of cortical circuits involved in active whisker sensory perception. Such a causal and mechanistic description of simple mammalian sensorimotor behaviors will form an essential step towards investigating mouse models of human brain diseases."