Adrian M. Corbett

My laboratory has three main areas of research: 1) excitation-contraction coupling research in skeletal muscle, 2) study of voltage-gated sodium channel subtypes in brain, with a particular interest in different localization, and 3) changes in ligand receptor density or neuronal activity in brain in response to stress, disease state, or environmental changes.

In excitation-contraction coupling research, my laboratory has used isolated triads from skeletal muscle to examine the effect of various compounds and ions on depolarization-induced calcium release. The triad is composed of a transverse tubule and two physically attached terminal cisternae of the sarcoplasmic reticulum. Chemically-induced depolarization of the transverse tubule initiates calcium release in a voltage-dependent manner from the calcium-loaded terminal cisternae, which is monitored through changes in Fura fluorescence.

My work on sodium channel subtypes in brain has resulted in the generation of subtype specific polyclonal antibodies, which have been used to study sodium channel subtype localization in the brain. This work has pointed to an interesting change in localization for the RII sodium channel subtype: in every area of the brain this channel is localized in unmyelinated axons EXCEPT in specific regions of the hypothalamus, which it is ALSO found on the neuronal soma and on dendrites. This suggests that signal for specific targeting of the RII sodium channel to unmyelinated axons may have been lost in these areas, resulting in localization of this channel all over the neuron cell membrane. My laboratory is pursuing isolation of RII sodium channels from the hypothalamus and intends to compare peptide digests of these channels with those which are normally targeted to unmyelinated neurons, through the use of reverse phase chromatography. [Image]

Finally, my laboratory has pursued some small projects with high school students in our Science Apprenticeship Program, using immunohistochemistry to identify changes in neuronal activity or receptor density in response to disease state, stress or environmental changes. In one project, we looked at changes in c-fos expression in rat brain following initiation of decompression sickness. In another project, we compared glutamate receptor density (AMPA and kainite receptor types) in the solitary tract nucleus in control rats versus spontaneously hypertensive rats.