Abstract
Aspartate and glutamate are the principal candidates for the excitatory neurotransmitter released by the lateral olfactory tract (LOT) in prepyriform cortex of the rat. Identity of action of the natural transmitter with exogenous glutamate and/or aspartate, however, has not yet been demonstrated. We show that bath-applied 2-amino-4-phosphonobutyric acid, a presumed specific glutamate antagonist, blocks LOT-stimulated prepyriform field potentials and single unit activity but not the single unit response to ionophoretically applied glutamate or aspartate in rat olfactory cortex slices. These results suggest that neither aspartate nor glutamate is the LOT transmitter. Responses to ionophoretically applied N-methyl-DL-aspartate, kainic acid, and DL-homocysteate were clearly decreased by 2-amino-4-phosphono-butyric acid. This suggests that these agents, usually presumed to be aspartate or glutamate agonists, act at different receptors than aspartate and glutamate.
This is a preview of subscription content, log in via an institution to check access.
References
Bradford, H. F., and Richards, C. D. (1976). Specific release of endogenous glutamate from piriform cortex stimulated in vitro.Brain Res. 105168–172.
Collins, G. G. S. (1979). Evidence of a neurotransmitter role for aspartate and gamma-aminobutyric acid in the rat olfactory cortex.J. Physiol 29151–60.
Cull-Candy, S. G., Donnellan, J. F., James, R. W., and Lunt, G. G. (1976). 2-Amino-4-phosphonobutyric acid as a glutamate antagonist on locust muscle.Nature 262408–409.
Curtis, D. R., Phillis, J. W., and Watkins, J. C. (1961). Action of amino acids on the isolated hemisected spinal cord of the toad.Br. J. Pharmacol. 16262–283.
Curtis, D. R., and Watkins, J. C. (1963). Acidic amino acids with strong excitatory actions on ammalian neurones.J. Physiol. (Lond.) 1661–14.
Davies, J., Evans, R. H., Francis, A. A., and Watkins, J. C. (1979). Excitatory amino acid receptors and synaptic excitation in the mammalian central nervous system.J. Physiol. (Paris) 75641–644.
Dunwiddie, T., Madison, D., and Lynch, G. (1978). Synaptic transmission is required for initiation of long-term potentiation.Brain Res. 150413–417.
Engberg, I., Flatman, J. A., Lambert, J. D. C. (1978). The action ofN-methyl-D-aspartic and kainic acids on motoneurones with emphasis on conductance changes.Br. J. Pharmacol. 64384–385.
Engberg, I., Flatman, J. A., Lambert, J. D. C. (1979). The actions of excitatory amino acids on motoneurones in the feline spinal cord.J. Physiol. (Lond.) 288227–261.
Harvey, J. A., Scholfield, C. N., Graham, L. T., and Aprison, M. H. (1975). Putative transmitters in denervated olfactory cortex.J. Neurochem. 24445–449.
Johnson, J. L., and Aprison, M. H. (1971). The distribution of glutamate and total free amino acids in thirteen specific regions of the cat central nervous system.Brain Res. 26141–148.
Legge, K. F., Randic, M., and Straughan, D. W. (1966). The pharmacology of neurones in the pyriform cortex.Br. J. Pharmacol. 2687–107.
Nadler, J. V., Vaca, K. W., White, W. F., Lynch, G. S., and Cotman, C. W. (1976). Aspartate and glutamate as possible transmitters of excitatory hippocampus afferents.Nature 260538–540.
Olney, J. W., and de Gubaroff, T. (1978). Extreme sensitivity of olfactory cortical neurons to kainic acid toxicity. In E. G. McGeer, J. W. Olney, and P. L. McGeer (eds),Kainic Acid as a Tool in Neurobiology, Raven Press, New York, pp. 201–217.
Richards, C. D., Russell, W. J., and Smaje, J. C. (1975). The action of ether and methoxyflorane on synaptic transmission in isolated preparations of the mammalian cortex (guinea-pig).J. Physiol. (Lond.) 248121–142.
Scott, J. W., and Stewart, W. B. (1979). Mechanisms of augmented field potential responses in the rat olfactory bulb.Brain Res. 16321–32.
White, W. F., Nadler, J. V., Hamberger, A., and Cotman, C. W. (1977). Glutamate as transmitters of hippocampus perforant pathways.Nature 270356–357.
Willis, J. A., Myers, P. R., and Carpenter, D. O. (1977). An ionophoretic module which controls electroosmosis.J. Electrophysiol. Tech. 6817–824.
Yamamoto, C., and Matsui, S. (1976). Effect of stimulation of excitatory nerve tract on release of glutamic acid from olfactory cortex slices in vitro.J. Neurochem. 26487–491.
Author information
Authors and Affiliations
Additional information
Supported by Armed Forces Radiobiology Research Institute, Defense Nuclear Agency, under Research Work Unit MJ 60203. The views presented in this paper are those of the authors. No endorsement by the Defense Nuclear Agency has been given or should be inferred.
Rights and permissions
About this article
Cite this article
Hori, N., Auker, C.R., Braitman, D.J. et al. Lateral olfactory tract transmitter: Glutamate, aspartate, or neither?. Cell Mol Neurobiol 1, 115–120 (1981). https://doi.org/10.1007/BF00736043
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00736043