The Cholinergic Ligand Binding Material of Axonal Membranes
Evidence has accumulated that acetylcholine (ACh) might play a role in axonal as well as in synaptic membranes. The postulate of Nachmansohn (23) that ACh triggers axonal as well as synaptic permeability changes has been a subject of controversy. However, cholinergic agonists and antagonists affect conduction at the nodes of Ranvier where permeability barriers to quaternary ammonium compounds are minimal (4, 12). Furthermore, choline acetyltransferase and acetylcholinesterase, the enzymes responsible for the synthesis and the hydrolysis of ACh, are present in nerve fibers. Also, in crustacean peripheral nerves release of ACh from cut nerve fibers could be demonstrated (13). Moreover, Denburg and his coworkers (10, 11) have prepared closed membrane vesicles from lobster walking leg nerve plasma membrane, and have demonstrated saturable binding of cholinergic agonists and antagonists to such membranes. Our laboratory has thus been engaged in studying this “axonal cholinergic binding material,” and in elucidating its functions.
KeywordsQuaternary Ammonium Compound Synaptic Membrane Cholinergic Agonist Axonal Membrane Planar Bilayer
Unable to display preview. Download preview PDF.
- 4.Chang,C.C. and Lee, C.J. (1966): Brit. J. Pharmacol. 28: 172–182.Google Scholar
- 7.Coronado, R. and Latorre, R. (1983): Biophys. J. 41: 56.Google Scholar
- 9.Dahlstrm, A.B. et al. This book.Google Scholar
- 10.Denburg, J.L. (1972): Biochim. Biophys. Acta 282: 453–458.Google Scholar
- 15.Jumblatt,J.E. and Mautner, H.G. (1980): Abstr. Am. Chem. Soc. Meet., Biol. Chem. Div.: 96.Google Scholar
- 22.Mueller, P. and Rudin, D.O. (1969): In Laboratory Techniques in Membrane Biophysics (eds) H. Passow and R. Stampfli,SpringerVerlag, Berlin, New York, pp. 141–156.Google Scholar
- 23.Nachmansohn, D. (1953): Harvey Lect., Ser. 49: 57–99.Google Scholar
- 24.Rama Sastry, B.V. and Sadavongvivad, C. (1978): Pharmacol. Revs. 30: 65–132.Google Scholar