Berkowitz Lab Research:
How does an animal's nervous system select and generate
an appropriate
behavior for each circumstance the animal faces? Our research addresses
this general
question through neurophysiological and
neuroanatomical
experiments on an especially suitable model system: the turtle
spinal cord. The turtle spinal cord can produce three distinct
types of rhythmic scratching movements of a hindlimb, each targeted to
a different region of the body, as well as two types of rhythmic
swimming movements of the hindlimbs. The programs for generating
these movements and for "choosing" among them reside in the spinal
cord: the animal can produce these movements
appropriately even
when all input from the brain is removed. This means that we can
focus attention on a relatively small subset of the central nervous
system and study the electrical activity and the morphology of
individual spinal cord neurons that are involved in selecting and
generating each type of movement. We can then reveal the kinds of
neural circuitry that allow the spinal cord to select and generate
appropriate movements.
Selected Publications:
Berkowitz, A. (2008) Physiology and morphology of shared and specialized spinal interneurons for locomotion and scratching. J. Neurophysiol. 99:2887-2901.
Berkowitz, A. (2007) Spinal interneurons that are selectively activated during fictive flexion reflex. J. Neurosci. 27:4634-4641.
Berkowitz, A., Yosten, G.L.C., and Ballard, R.M. (2006)
Somato-dendritic morphology predicts physiology for neurons that
contribute to several kinds of limb movements. J.
Neurophysiol. 95:2821-2831.
Berkowitz, A. (2005) Physiology and morphology indicate that individual
spinal interneurons contribute to diverse limb movements. J. Neurophysiol. 94:4455-4470.
Berkowitz, A. (2004) Propriospinal projections to the ventral horn
of the rostral and caudal hindlimb enlargement in turtles. Brain Res. 1014:164-176.
Berkowitz, A. (2002a) Both shared and specialized neural circuitry
for scratching and swimming in turtles. J. Comp. Physiol. A
188:225-234.
Berkowitz, A. (2002b) Endogenous biotin staining in a subset of
spinal neuronal cell bodies: a potential confounding factor for
neuroanatomical studies. Brain Res. 938:98-102.
Berkowitz, A. (2001a) Broadly tuned spinal neurons for each form of
fictive scratching in spinal turtles. J. Neurophysiol.
86:1017-1025.
Berkowitz, A. (2001b) Rhythmicity of spinal neurons activated during
each form of fictive scratching in spinal turtles. J. Neurophysiol.
86:1026-1036.
Berkowitz, A. and Stein, P.S.G. (1994a) Activity of descending
propriospinal axons in the turtle hindlimb enlargement during two forms
of fictive scratching: Broad tuning to regions of the body
surface. J. Neurosci.
14:5089-5104.
Berkowitz, A. and Stein, P.S.G. (1994b) Activity of descending
propriospinal axons in the turtle hindlimb enlargement during two forms
of fictive scratching: Phase analyses. J. Neurosci.
14:5105-5119.
Berkowitz, A. and Stein, P.S.G. (1994c) Descending propriospinal
axons in the hindlimb enlargement of the red-eared turtle: Cells of
origin and funicular courses. J. Comp. Neurol.
346:321-336.
Berkowitz, A. and Laurent, G. (1996a) Local control of leg movements
and motor patterns during grooming in locusts. J. Neurosci.
16:8067-8078.
Berkowitz, A. and Laurent, G. (1996b) Central generation of grooming
motor patterns and interlimb coordination in locusts. J. Neurosci.
16:8079-8091.
Berkowitz, A. (1996a) Our genes, ourselves? BioScience
46:42-51.
Berkowitz, A. (1996b) Networks of neurons, networks of genes. Neuron
17:199-202.
Vu, E.T., Berkowitz, A., and Krasne, F.B. (1997) Postexcitatory
inhibition of the crayfish lateral giant neuron: a mechanism for
sensory temporal filtering. J. Neurosci. 17:8867-8879.
Berkowitz, A., Vu, E.T., and Krasne, F.B. (1998) Specificity of
neural circuits that inhibit escape in crayfish. Ann. NY Acad. Sci.
860:461-463.
Current research in the Berkowitz laboratory is
supported by a grant from the National Science Foundation.