 Songbird Neurophysiology Laboratory
Primary research interest:
Neurophysiology of Vocal Communication and
Songbird Models of Speech Disorders
Principal Investigator: Dr. Santosh A. Helekar
Co-Investigator: Dr. Delanthi Salgado-Commissariat
Current Projects:
- Development and study of animal models of speech problems such as stuttering using selective breeding, cross-tutoring and neuropharmacology ;
- Understanding how the brain encodes complex sensory percepts such as vocal sounds using electrophysiology and functional magnetic resonance imaging; and
- Investigation of brain mechanisms that govern vocal learning using acoustic analysis of song data, in vivo an in vitro electrophysiology and functional magnetic resonance imaging.
Research Assistants: Pemason Diep, Rey Langot and Sharnali Das
Lab Manager: Dr. Delanthi Salgado-Commissariat
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.
Contact information:
Santosh A. Helekar, M.D., Ph.D.
Director of Songbird Neurophysiology Laboratory
The Methodist Neurological Institute
6565 Fannin St., F764B
Houston, Texas 77030
Phone: (713) 441-3733
Fax: (713) 441-5130
Email: shelekar@tmh.tmc.edu
Neurophysiology of Vocal Communication and Songbird Models of Speech Disorders
| A basic understanding of how our brain gives us the ability to speak and to understand spoken sounds might be essential to discovering the causes and mechanisms of speech disorders. Complex behaviors and disorders can be best studied by using simple animal models. Birdsong in songbirds such as zebra finches turns out to be a very useful model of speech because of some striking similarities between the two. Both forms of vocal communication are comprised of a well-structured sound output, and are learned from tutors or peers during early development. They are dependent on integrity of hearing and auditory feedback. They are subject to a critical developmental period of acquisition, and they show analogous phases of maturation. |
An adult zebra finch couple. Orange patch on the
cheeks indicates a male.
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We are interested in zebra finch birdsong from the standpoint of:
- Developing and studying animal models of speech problems such as stuttering;
- Understanding how the brain encodes complex sensory percepts such as vocal sounds; and
- Investigating the mechanisms in the brain that govern vocal learning.
To pursue these research interests we are conducting a series of experiments utilizing a variety of advanced techniques in zebra finches such as functional magnetic resonance imaging (fMRI), electrophysiological recordings in awake behaving birds and in artificially maintained live brain slices, and long term computerized monitoring of birdsong learning.
HVC and RA (Robust nucleus of arcopallium) are song control nuclei. LMAN (Lateral magnocellular nucleus of anterior nidopallium), Area X and DLM form the song learning circuit. |
We have discovered that a variant birdsong containing repetitive syllable features that resemble part-word repetitions of stuttering can occur spontaneously in zebra finches. A vulnerable fraction of apparently normal birds can also acquire such a variant when tutored with it.
Spectrograms of zebra finch song motifs |
We have proposed that such birdsong variants might be regarded as an animal model of stuttering, and we hope to gain insights into its developmental, cellular and molecular bases.
Electrical recording of auditory evoked potentials using 12 electrode arrays
Our research is supported by the National Institute of Mental Health. Dr. Ofer Tchernichovski and Kristen Maul of the Department of Biology at City College of New York, are our collaborators in the behavioral and in vivo electrophysiological experiments. The fMRI studies are conducted in collaboration with Drs. Henning Voss and Doug Ballon at the Citigroup Biomedical Imaging Center and Department of Radiology of Cornell University Weill Medical College in New York. We have also initiated a joint research endeavor with Dr. Thiery Lints of the Department of Biology of Texas A&M University.
Functional magnetic resonance imaging of song stimulus evoked activation of the zebra finch brain
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Last Modified: May 8, 2007
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