Department of Neurology: Physicians & Scientists

Associate Research Professor of Neuroscience

Director of the Songbird Neurophysiology Laboratory
Methodist Neurological Institute
Department of Neurology

M.D. (1982) University of Bombay, Bombay, India
Ph.D. (1991) Baylor College of Medicine

6560 Fannin St. Suite 902
Houston, TX 77030
Phone: 713-441-3733
Fax:  713-441-5130
E-mail: SHelekar@tmhs.org

Research Interests: Vocal communication and sensory perception are important functions of the brain. Speech in humans and birdsong in songbirds such as zebra finches are dependent on learning from tutors or peers during early developmental stages of life. They are dependent on the proper functioning of the auditory pathway to process feedforward sound input and auditory feedback during this period. Auditory feedback is also important in maintaining the integrity of the vocal output in later stages of life. Production and acquisition of birdsong in zebra finches are governed by specialized posterior song control and anterior song learning pathways. Song perception is dependent on neural representation of sounds within central auditory nuclei as well as within some of the nuclei of the song control and song learning pathways. The birdsong system is therefore ideally suited to instruct us about sensorimotor integration and learning.

The Sonbird Neurophysiology Laboratory is primarily interested in contributing to the understanding of the neurophysiological basis of vocal communication and sensory perception by using the songbird zebra finch as a model system. We use electrophysiological, neuropharmacological and molecular neurochemical approaches combined with behavioral studies in zebra finches to study the neural aspects of learned song pattern variations resembling speech motor control disorders such as stuttering, and the neural representation of complex auditory stimuli. We are also interested more generally in studying the neural mechanisms of conscious perception.

Selected Publications:

• Voss, H. U., Tabelow, K., Polzehl, J, Tchernichovski, O., Maul, K. K., Salgado-Commissariat, D., Ballon, D. and Helekar, S. A. (2007) "Functional MRI suggests a lateralized topography of responses to song stimulation in the zebra finch brain". Proc. Nat. Acad. Sci. (U.S.A.) (in press).
• Salgado-Commissariat, D., Rosenfield, D. B. and Helekar, S. A. (2004) "Nicotinic receptor-mediated plasticity in robust nucleus of the archistriatum of the adult zebra finch". Brain. Res. 1018(1):97-105.
• Espino, G. G., Lewis, C., Rosenfield D. B. and Helekar, S. A. (2003) "Modulation of θ/α frequency profiles of slow auditory evoked responses in the songbird zebra finch". Neuroscience. 122(2):521-9.
• Helekar, S. A., Espino, G. G., Botas, A. and Rosenfield, D. B. (2003) "Development and adult phase plasticity of syllable repetitions in captive zebra finches". Behav. Neurosci. 117(5):939-51.
• Botas, A., Espino, G., Rosenfield, D. B. and Helekar S. A. (2001) "Reduction of female-directed song motifs induced by repeated singing in laboratory-bred zebra finches". Neurosci Lett. 297:203-206.
• Helekar, S. A., Marsh, S., Viswanath, N. and Rosenfield, D. B. (2000)"Acoustic pattern variations in the female-directed birdsongs of a colony of laboratory-bred zebra finches". Behav Process. 49:99-110
• Helekar, S.A. (1999) "On the Possibility of Universal Neural Coding of Subjective Experience". Conscious. Cogn. 8(4):423-446.
• Helekar, S.A. (1999) " In Defense of Experience-Coding Nonarbitrary Temporal Neural Activity Patterns". Conscious. Cogn. 8(4):455-461.
• Helekar, S.A. and Patrick, J. (1997) "The peptidyl prolyl cis-trans isomerase activity of cyclophilin A in homo-oligomeric receptor expression". Proc Natl Acad Sci USA. 94:5432-5437.

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Last Modified: September 25, 2007