Biomaterial Database

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. 1993

C J Heyser, and R E Hampson, and S A Deadwyler

Department of Physiology and Pharmacology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina.

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

UI	MeSH Term	Description	Entries
D007858	Learning	Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.	Phenomenography
D008297	Male		Males
D008568	Memory	Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.
D011597	Psychomotor Performance	The coordination of a sensory or ideational (cognitive) process and a motor activity.	Perceptual Motor Performance,Sensory Motor Performance,Visual Motor Coordination,Coordination, Visual Motor,Coordinations, Visual Motor,Motor Coordination, Visual,Motor Coordinations, Visual,Motor Performance, Perceptual,Motor Performance, Sensory,Motor Performances, Perceptual,Motor Performances, Sensory,Perceptual Motor Performances,Performance, Perceptual Motor,Performance, Psychomotor,Performance, Sensory Motor,Performances, Perceptual Motor,Performances, Psychomotor,Performances, Sensory Motor,Psychomotor Performances,Sensory Motor Performances,Visual Motor Coordinations
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D006624	Hippocampus	A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.	Ammon Horn,Cornu Ammonis,Hippocampal Formation,Subiculum,Ammon's Horn,Hippocampus Proper,Ammons Horn,Formation, Hippocampal,Formations, Hippocampal,Hippocampal Formations,Hippocampus Propers,Horn, Ammon,Horn, Ammon's,Proper, Hippocampus,Propers, Hippocampus,Subiculums
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001522	Behavior, Animal	The observable response an animal makes to any situation.	Autotomy Animal,Animal Behavior,Animal Behaviors
D013759	Dronabinol	A psychoactive compound extracted from the resin of Cannabis sativa (marihuana, hashish). The isomer delta-9-tetrahydrocannabinol (THC) is considered the most active form, producing characteristic mood and perceptual changes associated with this compound.	THC,Tetrahydrocannabinol,delta(9)-THC,9-ene-Tetrahydrocannabinol,Marinol,Tetrahydrocannabinol, (6a-trans)-Isomer,Tetrahydrocannabinol, (6aR-cis)-Isomer,Tetrahydrocannabinol, (6aS-cis)-Isomer,Tetrahydrocannabinol, Trans-(+-)-Isomer,Tetrahydrocannabinol, Trans-Isomer,delta(1)-THC,delta(1)-Tetrahydrocannabinol,delta(9)-Tetrahydrocannabinol,9 ene Tetrahydrocannabinol,Tetrahydrocannabinol, Trans Isomer