Areas of Interest
1) Oculomotor system, control of rapid eye movements by the
central Mesencephalic Reticular Formation (cMRF) and its
relationship to the superior colliculus. 2) Oculomotor system:
control of fixation. 3) Gaze system: Contribution of the cMRF to
the control of gaze. 4) Models of the oculomotor system.
Behavioral, neurochemical, and neurophysiologic techniques are
used to explore how cells in the cMRF, which have reciprocal,
topographic projections to the superior colliculus, participate
in the control of combined head and eye movements (i.e., gaze).
Our current hypothesis is that the cMRF participates in a
decomposition of the gaze signal originating from the superior
colliculus into separate head and eye streams. Single neuron
electrophysiology, gaze (eye re: head) and head (re: space)
movement measurements are used to examine whether the reticular
formation carries signals about the current position, velocity,
or acceleration of the head or eyes to the superior colliculus,
Pontine Reticular Formation (PPRF) or cervical spinal cord.
Reversible and irreversible lesions within the reticular
formation are utilized to characterize its role in oculomotor
control. Antidromic stimulation is used to confirm the target
structures of reticular formation neuronal activity. These
techniques provide data to model how the reticular formation
might participate in gaze control. Future projects include
correlation of neck EMG activity with the activity of neurons in
the cMRF.
Publications
Selected Publications
Waitzman, D. M., Pathmanathan, J., Presnell, R., Ayers, A.,
DePalma, S. The contribution of the Superior Colliculus and the
Mesencephalic Reticular Formation (MRF) to Gaze Control In:
Neurobiology of Eye Movements: From Molecules to Behavior (Eds:
H.J. Kaminski and R. J. Leigh) New York Academy of Sciences: New
York, In Press, 2002.
Waitzman, D. M., and Oliver, D. L., The Midbrain In: The
Encyclopedia of the Human Brain (Ed: V. S. Ramachandran),
Academic Press: San Diego, In Press, 2001.
Waitzman, D.M., Silakov V.L., DePalma-Bowles S.R., Ayers, A.S.
Effects of reversible inactivation of primate Mesencephalic
Reticular Formation. II. Hypometric vertical saccades. J.
Neurophysiol. 83:2285-2299, 2000.
Waitzman, D. M., Silakov, V. L., DePalma, S. R., Ayers, A.S.
Reversible inactivation of primate Mesencephalic Reticular
Formation (MRF): I. Hypermetric goal-directed saccades. J
Neurophysiol 2000a.
Waitzman, D.M., Silakov, V.L., DePalma, S.R., Ayers, A.S.
Reversible inactivation of primate Mesencephalic Reticular
Formation (MRF). II. Hypometric vertical saccades. J
Neurophysiol 2000b.
 View more publications, see
Pubmed listing. |
