Dr. Alan D. Grinnell
Synaptic Physiology and Biophysics
73-387 CHS
310- 825-4468
agrinnell@mednet.ucla.edu

Research Interests:

My research is aimed at understanding the regulation of synapse number, location, and strength, primarily using the neuromuscular junction as a model system. Current interest is centered on developing synapses in a Xenopus nerve-muscle cell culture system, where we use endogenous Ca++-dependent K+ (BK) channels as reporters to characterize the “Ca++ domains” that exist transiently at active zones during presynaptic activity, and correlate the magnitude and time course of release with local [Ca++]. We are also studying the changes that occur in the release properties of motor nerve terminals during development.  A second major interest is in the mechanism of robust mechanical  modulation of neurotransmitter release from frog motor nerve terminals by muscle stretch, and the role played by integrins and the presynaptic cytoskeleton. Finally, I have a long-time interest in the neural adaptations associated with echolocation in different species of bats.

Representative Publications:

Chen, B.M. and Grinnell, A.D. (1997) Kinetics, Ca++ dependence, and biophysical properties of integrin-mediated mechanical modulation of transmitter release from frog motor neerve terminals. J. Neurosci.  17:904-916

Yazejian, B.M., Sun, X.-P., and Grinnell, A.D. (2000) Tracking presynaptic Ca++ dynamics during neurotransmitter release with Ca++-activated K+ channels. Nature Neurosci. 3:566-571.

Sun, V.-P., Yazejian, B, and Grinnell, A.D. (2004) Electrophysiological properties of BK channels in Xenopus motor nerve terminals. J. Physiol. 557:207-228

Synapse in Xenopus 
Nerve-muscle cell culture

Freeze-etch of frog nmj