Our research is focusing on correlating physiological changes of brain micro-circuits with resulting anatomical changes. Currently I am studying how the induction of synaptic plasticity results in a change in the number of synapses made between a pair of neurons, and whether sub-synaptic receptor localization can account for the mechanisms of certain synaptic states. I am testing two competing hypotheses: whether 1) certain subtypes of glutamate receptors are sorted based on interactions with the unique amino acid sequence of each subunit's C-terminal tail (tail-sorting model); or 2) long term potentiation/ depression results from changes in postsynaptic density and/or the volume of the postsynaptic spine (indiscriminate model). Understanding these processes will help address a variety of issues in normal and pathological brain functions, including the basic molecular and cellular mechanisms of learning and memory formation.
In another ongoing project, I am characterizing the myelination of inhibitory neurons and explore its functional significance. Only some neuron types form myelinated axons, for example cortical pyramidal cells, cerebellar Purkinje cells, and parvalbumin-expressing subclass of basket interneurons. Surprisingly little is known about the structural and molecular organization of myelin on different neuron types. Our preliminary data reveal that there are significant differences between the myelin of inhibitory and excitatory axons in cortex. My future studies will further compare molecular and structural features of myelinated axons of PV basket cells and excitatory neurons in cortical gray matter, as well as their involvement in cortical plasticity and pathology (multiple sclerosis model).