Effect of delta 9-tetrahydrocannabinol on short-term memory in the rat.
We have reported that marihuana and its principal psycoactive compound, delta 9-tetrahydrocannabinol (delta 9-THC) produce alterations in several cerebral areas after acute treatment. Based on the involvement of 5-hydroxytryptamine (5-HT) on memory and learning and the reported effects of delta 9-THC on short-term memory, we designed an experiment to evaluate the memory performance and its possible relationship with serotonergic alterations after delta 9-THC administration. Male Wistar rats received an acute oral dose of THC (5 mg/kg). Short-Term memory was tested on a radial 8-arm maze with a 5 s delay, after 35 days of training. The animals were food deprived and adjusted for growth. 5-HT and its metabolite, 5-HIAA, levels were measured in cerebral cortex, dorsal hippocampus, ventral hippocampus, rostral neoestriatum and amygdala basal nucleus, by HPLC-ED. The experiment indicates an impairment of short-term memory in the radial maze test after delta 9-THC administration. The control group performed the test without errors, while the treated group made a significant number of errors (Z = 0.019, Mann-Whitney test). This behavioral effect did not seem to be related to serotonergic alterations, as the 5-HT turnover rate was not different between treated and control animals.
Molina-Holgado
F
F
Dpt. Biología Animal II, Facultad de CC. Biológicas, Universidad Complutense, Madrid, Spain.
González
M I
MI
Leret
M L
ML
D000284:Administration, Oral; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D001923:Brain Chemistry / Q000187:drug effects; D013759:Dronabinol / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008570:Memory, Short-Term / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000502:physiology
D012701:Serotonin; D013759:Dronabinol