Information transfer at the synapse, called synaptic transmission, is critical for proper brain function. Neuromodulatory systems play an important role in regulating synaptic function and plasticity, and dysregulation of these mechanisms underlies several neurological disorders and pathological conditions. While synaptic factors that tune excitatory and inhibitory synapses vary widely over neuronal circuitries, the relative importance of these factors in determining brain activity is not well understood.
The main interest of my lab is to understand the cellular and molecular events by which endogenous neuromodulators tune synaptic transmission and plasticity at excitatory and inhibitory synapses. To this end, we investigate how different neuromodulatory systems (e.g. endocannabinoids, opioids, serotonin, and dopamine) regulate synaptic function by studying the biophysical and physiological properties of individual synapses within different neuronal circuits. In particular, we focus on the retinal circuitry, where modulation of synaptic function will have profound influence on how we see the external world. In addition, we examine the hippocampus and prefrontal cortex, where modulation of synaptic transmission affects higher cognitive processes such as learning and memory. We use a combination of tools including electrophysiology, optogenetics, in vivo knock-down strategies, and cellular biology approaches to understand: (1) the functional role of endocannabinoid signaling in retinal synaptic function; and (2) how serotonin receptors modulate excitatory and inhibitory synapses to regulate behavior. By studying the mechanisms underlying neuronal communication and its regulation by neuromodulators, we expect to uncover important principles of nervous system function at the cellular level, allowing us to integrate this information into a larger framework from which to investigate aspects of retinal disorders as well as neuropsychiatric disorders.