While considerable progress has been made in understanding the molecular and cellular foundations of nervous system function, much less is known about the integrative processes that give rise to behavior.  This situation is rapidly changing with the development of tools that allow nervous system activity to be monitored and manipulated in increasingly refined ways. Emerging tools for manipulation, in the form of genes that can be selectively expressed in subsets of neurons and whose products alter neuronal activity, are increasingly useful in mapping neuronal circuits in the fruit fly, where researchers have been able to take advantage of targeting techniques that afford reproducible, cell-type specific, and temporally restricted expression of genes of interest.  In Drosophila, it is now possible to repeatedly turn on or off specific subsets of neurons in living, behaving animals.

My laboratory is actively engaged in generating and exploiting methods for the identification and analysis of neuronal circuits. In addition to previously developed tools for the suppression and enhancement of neuronal activity, we recently introduced a new tool for acutely activating neurons in response to small decrements in temperature (see Peabody et al. (2009) J. Neurosci. 29: 3343-53). We have also developed a general method for systematically restricting transgene expression to permit refined targeting of small subsets of neurons (Luan et al. (2006) Neuron 52:425-436). The latter technique promises to permit the identification and characterization of neuronal circuits underlying behavior in unprecedented detail.  

We are applying these methods to map the neuronal circuit underlying wing expansion, a hormonally-governed process that must be coordinated both with the emergence of the adult animal from the pupal case and with environmental conditions upon emergence. The mechanisms by which extrinsic and intrinsic factors act on neuronal networks to orchestrate a specific behavioral output are thus naturally open to investigation in this system. Because the wing expansion program is innate, its circuitry also must be laid down during development and identifying the developmental genes that specify this circuitry is a further goal of the research conducted in my laboratory.
 

• Peabody, N. C., Pohl, J. B., Diao, F., Vreede, A. P., Sandstrom, D. J., Wang, H., Zelensky, P. K., and White, B. H. Characterization of the Decision Network for Wing Expansion in Drosophila Using Targeted Expression of the TRPM8 Channel. J. Neurosci. 29: 3343–53. 2009.
• Peabody, N. C., Diao, F., Luan, H., Wang, H., Dewey, E., Honegger, H-W., and White, B. H. Bursicon Functions within the Drosophila Central Nervous System to Modulate Wing Expansion Behavior, Hormone Secretion, and Cell Death.J. Neurosci. 28:14379-91. 2008.
• Gao, S., Takemura, S., Ting, C-Y., Huang, S., Lu, Z., Luan, H., Rister, J., Thum, A. S., Yang, M., Hong, S-T, Wang, J.W., Odenwald, W. F., White, B. H., Meinertzhagen, I. A., and Lee, C-H. The Neural Substrate of Spectral Preference in Drosophila. Neuron. 60: 328-42. 2008.
• Luan, H. and White B. H. Combinatorial Methods for Refined Neuronal Gene Targeting. Curr Opin Neurobiol. 17:572-80. 2007.
• Luan, H., Peabody, N.C., Vinson, C.R., and White B. H. Refined Spatial Manipulation of Neuronal Function by Combinatorial Restriction of Transgene Expression. Neuron. 52:425-436. 2006.