Interaction between impulse-flow and delta 9-tetrahydrocannabinol within the septal-hippocampal cholinergic pathway of rat brain.
The role of the cholinergic cell bodies of the medial septum in the transsynaptic reduction of nerve activity elicited by delta 9-tetrahydrocannabinol (THC) in the septal-hippocampal cholinergic pathway was assessed by measuring the ability of delta 9-THC to reduce sodium-dependent high affinity choline uptake in rat hippocampus 2 hr after electrolytic destruction of the cholinergic cell bodies in the septum. delta 9-THC did not reduce choline uptake in rats with electrolytic lesions of the cholinergic cell bodies in the septum. Because lesioning of cholinergic cell bodies itself reduces impulse-flow in cholinergic neurons, this observation has two interpretations: either delta 9-THC acts transynaptically at the cholinergic cell bodies in the septum, or alternatively, requires impulse-flow in the septal-hippocampal cholinergic pathway in order to reduce its activity. To test if delta 9-THC required impulse-flow in order to reduce the activity or the septal-hippocampal cholinergic pathway, the ability of delta 9-THC to reduce choline uptake in hippocampus of rats with cingulate bundle transections, another surgical procedure which reduces impulse-flow iun the septal-hippocampal cholinergic pathway, was measured. In cingulate bundle-transected rats, delta 9-THC did not reduce choline uptake in hippocampus. Taken together with the effects of delta 9-THC in septal-lesioned rats, this observation favors the interpretation that delta 9-THC requires impulse-flow in the septal-hippocampal cholinergic pathway in order to reduce the activity of this pathway.
D000818:Animals; D001921:Brain / Q000187:drug effects*; D002794:Choline / Q000378:metabolism; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D013759:Dronabinol / Q000494:pharmacology*; D006179:Gyrus Cinguli; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009434:Neural Pathways / Q000187:drug effects; D010275:Parasympathetic Nervous System / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000502:physiology
D013759:Dronabinol; D012964:Sodium; D002795:Choline O-Acetyltransferase; D002794:Choline