RESEARCH INTERESTS

I use the nematode Caenorhabditis elegans as a model organism for the following studies.

• Cellular diversity in the nervous system

          What makes neurons distinct from each other? Neurons are very diverse and there are trillions of them in the human brain, so investigating neuronal diversity is challenging.  The nervous system of nematode C. elegans has only 302 neurons with 118 classes and offers a simple start to understand neuronal diversity. My goal is to find those genes that are primarily active in a neuron type.  I use high throughput methods such as neuron-specific microarrays to achieve this. The real challenge is to find the function of genes in neurons, so, powerful genetic methods in the worm provide a bridge between genome-scale analysis and functional studies.

• Motor nervous system

         Worm’s movement is controlled by motor neurons that line along the body. We described a molecular signature for inhibitory GABAergic motor neurons using neuron-specific microarrays and identified members of a gene regulatory network specific to these cells. Following up the same analysis, I am currently investigating neuronal nicotinic signaling that is implicated in addiction behavior. Motor neurons in different species are likely to share basic molecular mechanisms due to evolutionary conservation, so insights from the worm motor neurons may help understand the biology of the spinal cord with possible therapeutic implications for spinal cord injury and neurodegenerative conditions.

• Nerve injury and regeneration in C. elegans

         To develop effective treatments for neurological diseases, we must understand how nerve cells regenerate. Animal models of nerve regeneration have been mostly limited to vertebrate organisms such as rodents and fish, but an alternative in the invertebrate worm is desirable because of tremendous research potential. Ultrashort (femtosecond) laser technology has recently made subcellular surgery possible. In collaboration with physicists, we created a nerve regeneration paradigm based on laser nanosurgery of the tiny GABAergic motor neurons. This method opens the following research venues:

• roles of major signaling pathways that are implicated in nerve regeneration

• in vivo testing of drug candidates

• study of laser-tissue interactions in live tissue and quality control for therapeutic lasers