Spotlight: Nedivi

What makes the brain grow?

Switch on a light in a dark room, and you unleash a series of chemical and structural changes in certain cells in your brain. Professor Nedivi's lab has found that for rodents, turning on that light triggers as many as six genes to start making specific proteins that allow those cells, in minute ways, to grow, branching toward each other with miniscule molecular fingers, precursors to the full-blown neuron-to-neuron links called synapses.

Like every cell in the body, neurons contain proteins for ordinary "housekeeping" jobs like burning sugar. But brain cells also contain several other kinds of proteins, including some crucial to the phenomenon of plasticity. These are created when certain genes in the brain are activated by outside stimuli—a light, a familiar face, the flavor of chocolate, an approaching soccer ball, Problem 36 on your calculus exam.

Using the powerful techniques of molecular biology, Elly Nedivi's lab aims to unravel which of the brain's genes are involved in making memories, and to detail how they work. From the full roster of genes expressed in the brain, the Nedivi lab has isolated 315 that probably play a role in memory. Given the painstaking work it will take to decode the work of each gene, it might be more "doable" to focus on two or three, but Professor Nedivi is convinced that memory-making is the work not of a few solitary genes but of a complex genetic ensemble. Proceeding on such a broad front may seem audacious, but it is calibrated to match the vast scale of the question—and it is the sort of calculated scientific daring the Picower Institute has fostered with great success.

Already, the Nedivi lab has identified a gene whose protein, surprisingly, has two distinct functions: promoting neuronal growth and helping the cell survive. This gene may play a pivotal role both as the brain develops and as memories form in later life. Building this fundamental understanding of how the brain works may eventually help scientists design highly targeted drugs for treating disorders like Alzheimer's, characterized by aggregations of abnormal proteins that kill off cells in the brain.