Changes in hippocampal CA1 population spikes following administration of delta-9-THC.
The effects of delta-9-tetrahydrocannabinol (delta-9-THC) on monosynaptic population responses in hippocampal CA1 pyramidal cells were examined in acute rats for several doses and at several post injection time periods. Delta-9-THC enhanced paired pulse inhibition in a dose-dependent manner; however biphasic dose effects were observed on cell responses during low frequency potentiation and on population spikes elicited by a conditioning stimulus. The biphasic responses were such that 2--4 mg/kg THC (IP) excited while 16 mg/kg depressed the stimulus elicited CA1 response. For low doses of THC slight biphasic time effects were observed. Evidence presented suggests that some of THC's actions on hippocampus may be due to direct or indirect actions on GABA-mediated activity.
D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects; D051381:Rats; D009435:Synaptic Transmission / Q000187:drug effects; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D005680:gamma-Aminobutyric Acid; D013759:Dronabinol