Duke Institute for Brain Sciences

The complex morphology of neurons, with their elaborately branched dendrites onto which impinge thousands of individual synapses, requires that highly specialized mechanisms exist for localizing, maintaining, and removing molecules at synapses. Such mechanisms are crucial for synapse formation during brain development, and for changes in synaptic strength that underlie learning-related plasticity. It is by now well established that synapses change in response to patterns of neural activity and these changes can endure, modifying neuronal circuitry. These competing properties of persistence and plasticity must be encoded by the content and arrangement of molecules that comprise the presynaptic and postsynaptic specializations. Our work focuses on two main themes that range from synapse biology and molecular genetics to in vivo physiology and behavior. First, we focus on highly compartmentalized membrane dynamics that occur at the postsynaptic membrane of excitatory glutamatergic synapses in the mammalian brain. Local membrane dynamics ensures that individual synapses can be modified while maintaining their unique and enduring molecular identity. Such mechanisms provide new insight into basic problems of molecular information storage. Second, we are using molecular genetic tools, imaging, and physiology, to monitor and manipulate neuronal populations in intact circuits of the mouse brain, focusing on the olfactory system and hippocampus. Our long term goal is to develop a cell biological understanding of circuit development and plasticity.

M.D., Johns Hopkins, 1998

Ph.D., Johns Hopkins, 1998

B.S., California Institute of Technology, 1991

B. R. Arenkiel, M. E. Klein, I. G. Davison, L. C. Katz, and M. D. Ehlers (2008). Targeted genetic control of neuronal activity in mice conditionally expressing TRPV1. Nature Methods. 5:299-302.

J. Lu, T. D. Helton, T. A. Blanpied, B. Racz, T. M. Newpher, R. J. Weinberg, and M. D. Ehlers (2007). Postsynaptic positioning of endocytic zones and AMPA receptor cycling by physical coupling of dynamin-3 to homer. Neuron 55:874-889.

M. D. Ehlers, M. Heine, L. Groc, M.-C. Lee, and D. Choquet (2007). Diffusional trapping of GluR1 AMPA receptors by input-specific synaptic activity. Neuron 54:447-460.