Exposure of hippocampal slices to quisqualate sensitizes synaptic responses to phosphonate-containing analogues of glutamate

• Published in: Brain research Vol. 381; no. 1; p. 187
• Main Authors: Robinson, M B, Whittemore, E R, Marks, R L, Koerner, J F
• Format: Journal Article
• Language: English
• Published: Netherlands 27-08-1986
• Subjects: 2-Amino-5-phosphonovalerate; Aminobutyrates - pharmacology; Animals; Evoked Potentials - drug effects; Glutamates - pharmacology; Hippocampus - drug effects; In Vitro Techniques; Male; Oxadiazoles - pharmacology; Quisqualic Acid; Rats; Rats, Inbred Strains; Stereoisomerism; Synapses - drug effects; Valine - analogs & derivatives; Valine - pharmacology
• ISSN: 0006-8993
• DOI: 10.1016/0006-8993(86)90711-0

Exposure of transverse slices of rat hippocampus to quisqualate (Quis) resulted in a marked increase in the potency of D- and L-2-amino-4-phosphonobutanoate (APB) and D- and L-2-amino-5-phosphonopentanoate (APV) for depression of extracellular synaptic field potentials recorded from CA1 pyramidal cells. L-APB depressed the amplitude of CA1 field potentials with an IC50 = 1800 microM before exposure to Quis. After a brief (4 min) exposure to sufficient Quis (16 microM) to depress the response by 50%, L-APB depressed these responses with an IC50 = 54 microM. These phosphonate-containing glutamate analogues transiently induced population-spiking after the tissue was pretreated with Quis. This suggests that APB and APV can act as agonists at micromolar concentrations.