What determines the amplitude and the time course of spontaneous excitatory unitary events is not well understood. Desensitization of fast AMPA/K channels has been shown to be fast enough to shorten individual quantal responses. However, it is not known whether the desensitization is uniform nor is it known what determines the relation between amplitude and rise or decay times in absence of desensitization. Both the rise and the decay times are essentially amplitude-independent in control conditions, but become markedly amplitude-dependent after desensitization has been suppressed by aniracetam. Strong amplitude-dependence of the rise and decay times suggests that in absence of desensitization the process(es) that determine(s) the time course of unitary events is/are concentration-dependent. Highly nonuniform, and strongly amplitude-dependent desensitization can be explained by its concentration dependence. The scatter of both rise and decay times about the best fitting lines was also amplitude-independent in control conditions. It increased markedly and in an amplitude-dependent manner after addition of aniracetam. The same factors that determine mean values probably determine the scatter as well.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.23400 |
| Date | January 1995 |
| Creators | Ghamari Langroudi, Masoud |
| Contributors | Glavinovic, Mladen I. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001481431, proquestno: MM12198, Theses scanned by UMI/ProQuest. |
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