Yuh Nung Jan
University of California, San Francisco
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Primary Section: 24, Cellular and Molecular Neuroscience Secondary Section: 22, Cellular and Developmental Biology Membership Type:
Member
(elected 1996)
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Research Interests
I have been interested in the function and development of the nervous system. Earlier on, my main focus was on neuronal function. I studied two problems: the first is the role of neuropeptides as signaling molecules between neurons. We found that although neuropeptides are released from peptidergic neurons at the synaptic sites as in the case of other conventional neurotransmitters (e.g., acetylcholine), they can diffuse and act on neighboring neurons that are not in direct synaptic contact with the peptidergic neuron. The implication is that in considering the wiring diagram of a nervous system, one has to take into account the neuropeptide's ability of "action at a distance." The second deals with the structure and function of potassium channels, which play key roles in controlling neuronal excitability and synaptic efficacy. More recently, my main interest has turned to the development of the nervous system. By using Drosophila, we were able to identify key molecules involved in controlling neuronal cell fates. For instance, a group of basic-helix-loop-helix transcriptional regulators such as "daughterless" and "atonal" function to initiate neural development and make neurons different from other cell types. We also began to understand the basis of asymmetric cell division, which allows a mother cell to give rise to two daughter cells with distinct cell fates. Since asymmetric cell division is the basis for generating diversity of cell types, this is a fairly fundamental problem in developmental biology.
