Modulation of Glutamate Responses by Noradrenaline and GABA in Neo- and Archicortical Structures
The excitatory neurotransmitter glutamate, the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), and the neuromodulator noradrenaline (NA) have been found to be involved in the pathophysiology of several neuropsychiatric disorders, especially schizophrenia and epilepsy (cf. Nistico et al., 1986). In epilepsy glutamate may contribute to the expression and spread, and GABA to the restriction, of epileptic discharges. NA has been reported to inhibit epileptic activity in different experimental conditions (cf. Przegalinski, 1985). The aim of the study reported here was to analyze the influence of NA and GABA on the action of the glutamate subreceptor agonist N-methyl-D-aspartate (NMDA). The experiments were performed in the motorcortex of the rat (in vivo studies) and in neocortical organotypic tissue cultures of newborn rats, as well as in hippocampal slice preparations of guinea pigs (in vitro studies) using changes of field potentials and of membrane potential, respectively, as indicators.
KeywordsExcitatory Amino Acid Membrane Potential Change Inositol Phospholipid GABAB Receptor Agonist NMDA Response
Unable to display preview. Download preview PDF.
- Bingmann D, Baker R, Ruijter JM, Walden J, Speckmann E-J, Straub H (1989): Polyphasic membrane potential changes induced by GABA in neocortical and hippocampal neurons (in vitro). Eur J Neurosci (Suppl) 2: 110Google Scholar
- Connors BW, Malenka RC, Silva LR (1988): Two inhibitory postsynaptic potentials, and GABAA and GABAB receptor-mediated responses in neocortex of rat and cat. J Physiol 406: 443–468Google Scholar
- Nistico G, Morselli PL, Lloyd KG, Fariello RG, Engel J, eds. (1986): Neurotransmitters, Seizures and Epilepsy, Vol. 3. New York: Raven PressGoogle Scholar
- Przegalinski E (1985): Monoamines and the pathophysiology of seizure disorders. In: Handbook of Experimental Pharmacology: Vol. 74. Antiepileptic Drugs, Frey H-H, Janz D, eds. New York: SpringerGoogle Scholar
- Speckmann E-J, Walden J, Bingmann D, Lehmenkühler A, Altrup U (1990): Mechanisms underlying generalized tonic clonic seizures in the rat: Functional significance of calcium ions. In: Generalized Seizures, Avoli M, Gloon P, eds. Boston: BirkhäuserGoogle Scholar
- Walden J, Speckmann E-J, Bingmann D, Straub H (1991): Increase of glutamate responses by GABA in neocortical and archicortical structures. In: Physiology, Pharmacology and Development of Epileptogenic Phenomena, Klee MR, Lux HD, Speckmann E-J, eds. Berlin: Springer-VerlagGoogle Scholar