Our laboratory's major interest is the in the mechanisms responsible for the development and plasticity of precise connections within the central nervous system, and particularly in the role of neural activity in this process. Most of the work of the laboratory is on the visual cortex of the mouse. In our experiments, we induce activity-dependent plasticity experimentally through manipulations of genetics or experience or by pharmacological or neurophysiological intervention in order to discover what cellular mechanisms and what changes in cortical circuitry are responsible for rapid, long lasting changes in neuronal responses. We analyze these changes primarily in alert animals using microelectrode recordings, optical and metabolic signals related to neural activity, and anatomical and neurochemical tracing of connections. We seek to understand the coupling between the physiological and anatomical changes responsible for neuronal plasticity and the cellular mechanisms responsible for activity-dependent plasticity in the neocortex. A major goal is to understand how the limited plasticity in the adult brain differs from the much greater plasticity during critical periods in early life.

Current experiments focus on three issues: (1) discovering the neural circuit substrates of the adult plasticity responsible for perceptual learning and its regulation by cortical state, (2) elucidating the mechanisms by which transplantation of embryonic inhibitory neurons induces juvenile levels and forms of plasticity in adult animals, and (3) characterizing central visual responses to non-traditional stimuli using novel mathematical approaches that we hope will reveal cortical circuits.