The synthetic cannabinoid HU210 induces spatial memory deficits and suppresses hippocampal firing rate in rats
Open Access
- 1 July 2007
- journal article
- Published by Wiley in British Journal of Pharmacology
- Vol. 151 (5), 688-700
- https://doi.org/10.1038/sj.bjp.0707273
Abstract
Background and purpose: Previous work implied that the hippocampal cannabinoid system was particularly important in some forms of learning, but direct evidence for this hypothesis is scarce. We therefore assessed the effects of the synthetic cannabinoid HU210 on memory and hippocampal activity. Experimental approach: HU210 (100 μg kg‐1) was administered intraperitoneally to rats under three experimental conditions. One group of animals were pre‐trained in spatial working memory using a delayed‐matching‐to‐position task and effects of HU210 were assessed in a within‐subject design. In another, rats were injected before acquisition learning of a spatial reference memory task with constant platform location. Finally, a separate group of animals was implanted with electrode bundles in CA1 and CA3 and single unit responses were isolated, before and after HU210 treatment. Key results: HU210 treatment had no effect on working or short‐term memory. Relative to its control Tween 80, deficits in acquisition of a reference memory version of the water maze were obtained, along with drug‐related effects on anxiety, motor activity and spatial learning. Deficits were not reversed by the CB1 receptor antagonists SR141716A (3 mg kg‐1) or AM281 (1.5 mg kg‐1). Single unit recordings from principal neurons in hippocampal CA3 and CA1 confirmed HU210‐induced attenuation of the overall firing activity lowering both the number of complex spikes fired and the occurrence of bursts. Conclusions and implications: These data provide the first direct evidence that the underlying mechanism for the spatial memory deficits induced by HU210 in rats is the accompanying abnormality in hippocampal cell firing. British Journal of Pharmacology (2007) 151, 688–700; doi:10.1038/sj.bjp.0707273This publication has 58 references indexed in Scilit:
- Prolonged cannabinoid treatment results in spatial working memory deficits and impaired long‐term potentiation in the CA1 region of the hippocampus in vivoEuropean Journal of Neuroscience, 2004
- International Union of Pharmacology. XXVII. Classification of Cannabinoid ReceptorsPharmacological Reviews, 2002
- Long-term study of chronic oral aluminum exposure and spatial working memory in rats.Behavioral Neuroscience, 2002
- Locomotor activity and occupancy of brain cannabinoid CB1 receptors by the antagonist/inverse agonist AM281Synapse, 2000
- D2 dopamine receptors enable Δ9 -tetrahydrocannabinol induced memory impairment and reduction of hippocampal extracellular acetylcholine concentrationBritish Journal of Pharmacology, 2000
- Delay-dependent impairment of a matching-to-place task with chronic and intrahippocampal infusion of the NMDA-antagonist D-AP5Hippocampus, 1999
- Detailed behavioral analysis of water maze acquisition under systemic NMDA or muscarinic antagonism: Nonspatial pretraining eliminates spatial learning deficits.Behavioral Neuroscience, 1996
- Distinct components of spatial learning revealed by prior training and NMDA receptor blockadeNature, 1995
- Reversible effects of acute and long-term administration of Δ-9-tetrahydrocannabinol (THC) on memory in the ratDrug and Alcohol Dependence, 1991
- Learning impairment in the radial-arm maze following prolonged cannabis treatment in ratsPsychopharmacology, 1982