Scott Chandler, Ph.D.

Work Address:
610 Young Dr.
Los Angeles, CA 90095 610 Young dr-east
Los Angeles, CA 90095

Professor of Neuroscience, Integrative Biology and Physiology
Member, Brain Research Institute, Molecular, Cellular & Integrative Physiology GPB Home Area, Neuroscience GPB Home Area
Research Interests
My interests are in the area of neuronal mechanisms controlling rhythmical jaw movements that occur during such behaviors as feeding, drinking and swallowing. These are all behaviors essential for normal, meaningful human existence. Using rat and guinea pig models, I am interested in elucidating the location of, and cellular connectivity of the central circuits, as well as the neurochemical and physiological mechanisms underlying the control of excitability of the neurons within these circuits which are responsible for the production of jaw movements. Our approach is to use electrophysiological, pharmacological and anatomical techniques in both whole animal and in vitro brain slice preparations. Utilizing these techniques we have located the critical regions and premotoneurons responsible for the rhythmogenesis of mastication to a narrow area within the ponto-medullary brainstem. Investigations into the roles of excitatory amino acid receptor subtypes in production of jaw movements showed that both NMDA and nonNMDA receptors are important in the initiation and control of rhythmical jaw movements. The ionic conductances available to masticatory interneurons and motoneurons have been characterized as well as the modulation of these conductances by various neuromessengers. Additionally, we recently found a group of interneurons around the trigeminal motor nucleus which have intrinsic burst generation properties. These neurons could serve as the fundemental unit for rhythmogenesis during jaw movements. Progress in these areas will allow us to ultimately understand organizing principles utilized by the mammalian CNS with respect to motor production and to determine potential therapeutic interventions for the correction of abnormal jaw movements which occurs as a result of injury or disease.

A selected list of publications:

Hsiao, CF Wu, N Chandler, SH   Voltage-dependent calcium currents in trigeminal motoneurons of early postnatal rats: modulation by 5-HT receptors Journal of neurophysiology. , 2005; 94(3): 2063-72.
Wu, N Enomoto, A Tanaka, S Hsiao, CF Nykamp, DQ Izhikevich, E Chandler, SH   Persistent sodium currents in mesencephalic v neurons participate in burst generation and control of membrane excitability Journal of neurophysiology. , 2005; 93(5): 2710-22.
Tanaka, S Wu, N Hsaio, CF Turman, J Chandler, SH   Development of inward rectification and control of membrane excitability in mesencephalic v neurons Journal of neurophysiology. , 2003; 89(3): 1288-98.
Wu, N Hsiao, CF Chandler, SH   Membrane resonance and subthreshold membrane oscillations in mesencephalic V neurons: participants in burst generation The Journal of neuroscience : the official journal of the Society for Neuroscience. , 2001; 21(11): 3729-39.
Del Negro, C.A., Hsiao, C.F., and Chandler, S.H.   Outward currents controlling bursting dynamics in guinea pig trigeminal motoneurons, J. Neurophysiology, 1999; 81: 1478-1485.
Del Negro, CA Hsiao, CF Chandler, SH Garfinkel, A   Evidence for a novel bursting mechanism in rodent trigeminal neurons Biophysical journal. , 1998; 75(1): 174-82.
Hsiao, CF Del Negro, CA Trueblood, PR Chandler, SH   Ionic basis for serotonin-induced bistable membrane properties in guinea pig trigeminal motoneurons Journal of neurophysiology. , 1998; 79(6): 2847-56.
Del Negro, CA Chandler, SH   Physiological and theoretical analysis of K+ currents controlling discharge in neonatal rat mesencephalic trigeminal neurons Journal of neurophysiology. , 1997; 77(2): 537-53.