Effects of delta-9-tetrahydrocannabinol on delayed match to sample performance in rats: alterations in short-term memory associated with changes in task specific firing of hippocampal cells.

摘要: The effects of delta-9-tetrahydrocannabinol (delta-9-THC) were studied during performance a delayed match to sample (DMTS) task in rats. Correlated hippocampal cellular activity was also assessed terms the cannabinoids on well characterized specific changes firing rate which occurred various phases DMTS trial. Results show surprising correlation between delay and dose (0.75-2.0 mg/kg)-dependent behavioral deficit produced by delta-9-THC this similar damage hippocampus related structures. However, unlike lesions or neurotoxic damage, completely reversible within 24 hr injection. Neither control injection vehicle nor equivalent concentrations nonpsychoactive cannabinoid, cannabidiol, alterations levels. Simultaneous recordings from identified complex spike cells at highest drug indicated that associated with decrease cell discharge Sample (but not Match) phase task. In nine neurons (including four observed both conditions) recorded six different animals manifested, no indication observed. Although there slight but significant reductions Match Reinforcement THC sessions, highly increases these still present, indicating elimination did reflect nonspecific effect activity. These findings strongly suggest selectively impaired lack trial, could serve as basis for short-term memory other cognitive deficits reported humans after smoking marijuana.