The goal of this project is to improve our understanding of the transmitter release process and the means of regulating presynaptic events in nerve cells. The approach entails the reconstitution of a neuronal transmitter release system using the oocytes of Xenopus laevis. These oocytes can be microinjected with a wide range of materials, and importantly, have been shown to translate exogenously supplied messenger RNA. The reconstruction of the release process involves three phases. First, oocytes will be injected with messenger RNA from electromotor neurons of Torpedo or Narcine. This step may be crucial for endowing oocytes with components needed to support the exocytotic discharge of transmitter. The oocyte will then be injected with synaptic vesicles isolated from the electroplax tissue of Torpedo or Narcine. Finally, the oocytes will be stimulated electrically or chemically to determine whether evoked release of transmitter (acetylcholine) can be detected. Success of this reconstitution effort will facilitate a detailed examination of the molecular components involved in transmitter secretion. The resulting observations may open new avenues to the study of biochemical correlates of synaptic plasticity. Moreover, a wide range of neurological deficits (eg., dementia, Parkinsonism, mental retardation) might be amenable to scrutiny in a new light.
| Umbach, J A; Grasso, A; Gundersen, C B (1990) Alpha-latrotoxin triggers an increase of ionized calcium in Xenopus oocytes injected with rat brain mRNA. Brain Res Mol Brain Res 8:31-6 |
| Umbach, J A; Gundersen, C B (1989) Mercuric ions are potent noncompetitive antagonists of human brain kainate receptors expressed in Xenopus oocytes. Mol Pharmacol 36:582-8 |
| Gundersen, C B; Umbach, J A; Swartz, B E (1988) Barbiturates depress currents through human brain calcium channels studied in Xenopus oocytes. J Pharmacol Exp Ther 247:824-9 |
| Umbach, J A; Gundersen, C B (1987) Expression of an omega-conotoxin-sensitive calcium channel in Xenopus oocytes injected with mRNA from Torpedo electric lobe. Proc Natl Acad Sci U S A 84:5464-8 |
| Hediger, M A; Ikeda, T; Coady, M et al. (1987) Expression of size-selected mRNA encoding the intestinal Na/glucose cotransporter in Xenopus laevis oocytes. Proc Natl Acad Sci U S A 84:2634-7 |
