Venkatesh Murthy, Ph.D.

Professor of Molecular and Cellular Biology

Harvard University Biological Laboratories

The vast capacity of the brain to process and store information arises from the large number of neurons and their synaptic connectivity.

Research in our laboratory is motivated by general questions of how synapses operate and how they contribute to information processing and adaptation in circuits. While much of our past research has been in simple and accessible model systems in vitro, our current and future work centers on intact circuits in the rodent brain.

We continue to investigate mechanisms underlying activity-dependent synaptic plasticity in the rodent hippocampus, with an emphasis on inhibitory synapses. We are particularly interested in a phenomenon called homeostatic synaptic plasticity, which acts to compensate for chronic imbalances in neural activity. Our experiments aim to uncover rules and mechanisms by which persistent changes in activity alter different classes of inhibitory synapses.

The rodent olfactory brain (the olfactory bulb and piriform cortex) is now a target of significant effort in our lab. We develop and use novel optical and physiological methods in the living animal to seek answers to the following general questions: (1) How is odor information represented in the early stages of the olfactory system? (2) What is the logic of functional synaptic circuits in the early stages of the olfactory system? (3) How is information processing affected by different brain states - sleep, wakefulness and neuromodulation? (4) How are functional circuits in the olfactory system regulated by odor experience?

References:

• Tyler, WJ, Petzold, GC, Pal, SK and Murthy, VN. 2007. Experience-dependent modification of primary sensory synapses in the mammalian olfactory bulb. J. Neurosci. 27:9427-9438.

• Hartman, KN† , Pal, SK†, Burrone, J.and Murthy, V.N. 2006. Activity-dependent regulation of inhibitory synaptic transmission in hippocampal neurons. Nature Neuroscience. 9:642-649. † - equal contributors

• Dietz SB, Murthy VN. (2005). Contrasting short-term plasticity at two sides of the mitral-granule reciprocal synapse in the mammalian olfactory bulb. J Physiol 569:475-488.

• Li, Z., Burrone, J., Tyler, W.J., Hartman, K.N., Albeanu, D.F. and Murthy, V.N. (2005). Synaptic vesicle recycling studied using transgenic mice expressing synaptopHluorin. Proc. Natl. Acad. Sci. USA. 102:6131-6136.

• Murthy, V.N. and De Camilli, P. (2003). Cell biology of the presynaptic terminal. Annu. Rev. Neurosci. 26:701-728.

• Burrone, J., O'Byrne, M. and Murthy, V.N. (2002). Multiple forms of synaptic plasticity triggered by selective suppression of activity in individual neurons. Nature 420:414-418.