Postural reflexes are evoked and controlled by a variety of sensory inputs. The vestibulo-spinal (VS) pathways carry sensory vestibular signals to widespread regions of the spinal cord where they interact with motor nuclei to produce reflexive movement. This laboratory studies the vestibulo-collic reflexes (VCR), which are an important subset of postural reflexes that avert potential neck injury by reorienting the head during perturbations of the body. These mechanisms are studied using a variety of electrophysiological techniques for relating the response properties of the vestibulospinal neurons to functional aspects of the behavior and to the muscular activity used to produce the behavior. The functional aspects of the behavior to a certain extent depend on the behavioral context in which the reflex was evoked. Newer studies will investigate whether and how the signals arising from the vestibulospinal pathways participate in modifying the performance of reflexes during different behavioral contexts. We seek to understand the signal processing carried out by the spinal pathways and to relate it to the motor activity used to produce the reflex by correlating simultaneously recorded electromyography of neck muscles with neural activity. The results of these studies are not only significant to our understanding of the sensory-motor control of head movements but are also globally applicable to the control of all vestibular postural reflexes because their mechanisms likely utilize similar neural processing strategies.

Pub Med Citations

Reynolds, J.S. and Gdowski G.T. 2005 The effect of passive torque on the kinematics of vestibular-evoked reflexive head movements. IEEE Trans. The 2nd international IEEE EMBS special topic conference on neural engineering, In press 2005.

McCrea RA, Gdowski GT. 2003 Firing behaviour of squirrel monkey eye movement-related vestibular nucleus neurons during gaze saccades. J Physiol. 2003 Jan 1;546(Pt 1):207-24.

McCrea, R.A., Gdowski, G.T. and Luan H. 2001, Current concepts of vestibular nucleus function: Transformation of vestibular signals in the vestibular nuclei. Ann. NY Acad. Sci., In press.

McCrea, R.A. and Gdowski, G.T. 2001, The role of the tonic neck-eye reflex in gaze control. Int. J. of Posture and Gait, In press.

Gdowski, G.T., Belton, T., and McCrea, R. A. 2001, Neurophysiological substrate for the cervical-ocular reflex in the squirrel monkey. Exp. Brain Res., In press .

Gdowski, G.T., and McCrea, R. A. 2000, Neck proprioceptive inputs to primate vestibular nucleus neurons, Exp. Brain Res. 135(4):511-26.

Gdowski, G.T., Boyle, R., and McCrea, R. A. 2000, Sensory processing in the vestibular nuclei during active head movements. Arch. Ital. Biol. 138(1):15-28.

Gdowski, G.T. and McCrea, R. A. 1999, Open-loop versus closed-loop control of reflexive head movements. IEEE Trans. 504:544.

McCrea, R. A., Gdowski, G.T., Boyle, R., and Belton, T. 1999, Firing behavior of vestibulo-spinal and other non-eye-movement related vestibular neurons during active and passive head movements. J Neurophys. 81: 416-428.

Gdowski, G.T., and McCrea, R. A.1999, Integration of Vestibular and Head Movement Signals in the Vestibular Nuclei during Whole Body Rotation. J. Neurophys., 81: 436-449.

Gdowski, G.T., and Voigt, H.F.1998, Intrinsic oscillations and discharge regularity of units in the dorsal cochlear nucleus of the barbiturate anesthetized gerbil. Ann. Biomed.Eng., 26(3):473-87,

Gdowski, G.T., and Voigt, H.F. 1997, Response map properties of units in the dorsal cochlear nucleus of the barbiturate anesthetized gerbil (meriones unguiculatus). Hear. Res., 105(1-2):85-104.

McCrea, R.A., Chen-Huang, C., Belton, T., and Gdowski, G.T. 1996, Behavior contingent processing of vestibular sensory signals in the vestibular nuclei. In: Highstein, S.M., Cohen, B., Buttner-Ennever, J.A., eds. New Directions in Vestibular Research, Annals of the New York Academy of Sciences, vol 781, pp 292-303.