Dr. Richard B. Levine

Professor of Neuroscience and Physiology

Ph.D. 1978, State University of New York

Office:	Gould-Simpson Bldg. Rm. 427
E-mail:	This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Phone:	(520) 621-6654
Fax:	(520) 621-8282

Levine Lab Group

Development and hormonal regulation of neurons and neural circuits

People in the Levine laboratory are united by a common interest in the development and function of motor systems. We approach questions of relevance to all nervous systems by exploiting the powerful molecular and genetic tools that are available in the insect, Drosophila, as well as the advantages afforded by larger insects for studies involving electrophysiology.

During metamorphosis, many of the neurons that participate in larval behavior persist to become incorporated into the neuronal circuits of the adult. To accommodate changes in behavior, these neurons modify their dendritic structures, synaptic interactions, and biophysical properties. One goal of the laboratory is to understand the behavioral relevance of such changes by following the metamorphic fates of identified neurons and the circuits in which they are involved. For example, some motoneurons of the larva that participate in crawling survive the degeneration of their target muscles to innervate new adult muscles that participate in walking behavior, whereas others persist to innervate new flight muscles of the adult. In other cases, such as the neurons that control adult heartbeat in Drosophila, novel circuits are formed. Structural modifications, such as the growth of new dendrites and axonal ramifications, and functional changes, such as alterations in membrane currents and synaptic connectivity by the motoneurons, are linked to the development and production of new behavior.

A second goal is to characterize the molecular and cellular pathways through which these developmental changes are regulated and mediated. For example, we have shown that the steroid hormone, 20-hydroxyecdysone (20E) directs the reorganization of circuits during metamorphosis by inducing the growth of new neuronal processes and the formation of new synaptic connections that are important for new components of behavior, thereby providing a useful model for examining the basic mechanisms underlying comparable steroid-mediated alterations in more complex nervous systems. We are investigating the molecular pathways through which steroid hormones and neuronal activity regulate dendritic growth and ion channel expression through the use of mutant and transgenic animals. A wide range of experimental approaches, including intracellular and patch-clamp recording, confocal microscopy and immunocytochemistry both in vivo and in cell culture, are used to address these fundamental questions.

Selected Recent Publications

Hartwig C, Worrell J, Levine RB, Ramaswami M, and Sanyal S. Jun 2008. Normal dendrite growth in Drosophila motor neurons requires the AP-1 transcription factor.. Devel Neurobiology, 68 (10):1225-45

Worrell JC, and Levine RB. Jun 2008. Characterization of Voltage-Dependent Ca2+ Currents in Identified Drosophila Motoneurons in situ.. J Neurophysiology, 100:868-878

Barbee SA, Estes PS, Cziko AM, Hillebrand J, Luedeman RA, Coller JM, Johnson N, Howlett IC, Geng C, Ueda R, Brand AH, Newbury SF, Wilhelm JE, Levine RB, Nakamura A, Parker R, Ramaswami M. Dec 2006. Staufen- and FMRP-containing neuronal RNPs are structurally and functionally related to somatic P bodies. Neuron, 52:997-1009

Miller JE Levine RB. Oct 2006. Steroid hormone activation of wandering in the isolated nervous system of Manduca sexta. J Comp Physiol A Neuroethol Sens Neural Behav Phys, 192:1049-62

Dulcis D, Levine RB, Ewer J. Sep 2005. Role of the neuropeptide CCAP in Drosophila cardiac function. J Neurobiol, 64:259-74

Consoulas C, Levine RB, Restifo LL. May 2005. The steroid hormone-regulated gene Broad Complex is required for dendritic growth of motoneurons during metamorphosis of Drosophila. J Comp Neurol, 485:321-37

Dulcis D, Levine RB. Jan 2005. Glutamatergic innervation of the heart initiates retrograde contractions in adult Drosophila melanogaster. J Neurosci, 25:271-80

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