Accession Number : ADA187454

Title :   Mechanisms of Transmitter Release in Hippocampus: University Research Instrumentation Program.

Descriptive Note : Final rept. 1 Jul 86-30 Jun 87,

Corporate Author : BAYLOR COLL OF MEDICINE HOUSTON TX

Personal Author(s) : Johnston, Daniel

PDF Url : ADA187454

Report Date : 10 Sep 1987

Pagination or Media Count : 2

Abstract : This grant was for the purchase of equipment to establish a subcellular fractionation and patch clamping facility at Baylor College of Medicine. Experiments involve the isolation of an enriched fraction of mossy fiber synaptic terminals from adult rats. We have been investigating mechanisms of transmitter release, using biochemical and electrophysiological techniques. We have used the centrifuges successfully to develop this preparation of enriched mossy fiber synaptosomes. The computer, microscope, and isolation table are in use as a patch clamping facility to study the electrophysiological properties of these terminals. We have successfully measured the potassium stimulated and calcium dependent release of endogenous glutamate from these terminals. We have found that several phorbol esters are able to potentiate this release of glutamate, and we are in the process of investigating the mechanisms underlying this enhanced release. Our patch clamping has met with only limited success thus far. Although we have shown that the technique can be successfully applied to these small terminals, we have yet to make recordings of single calcium channels. The channels recorded thus far appear to be nonselective cation channels. We are currently in the process of altering our procedures and are hopeful that this aspect of the project will meet with more success in the very near future.

Descriptors :   *HIPPOCAMPUS, *NERVE TRANSMISSION, *NEUROCHEMISTRY, ADULTS, BIOCHEMISTRY, CALCIUM, CELLS(BIOLOGY), CENTRIFUGES, CHANNELS, ELECTROPHYSIOLOGY, ESTERS, FACILITIES, FIBERS, FRACTIONATION, GLUTAMIC ACID, INSTRUMENTATION, ISOLATION, MEDICINE, METHODOLOGY, PROCUREMENT, RATS, RELEASE, SALTS, SYNAPSE, TERMINALS, UNIVERSITIES, REACTION KINETICS

Subject Categories : Anatomy and Physiology
      Biochemistry
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE