
The endocannabinoid CB(1) receptor has been implicated in the inhibitory control of learning and memory. In the present experiment, we compared the behavioral response of CB(1) receptor knockout mice (CB(1)R(-/-)) with animals administered CB(1) receptor antagonist/inverse agonist SR141716A (rimonabant; 3 mg/kg IP, 30 min pre-trial) in terms of acquisition and retention of a habituation task and changes in cerebral monoamines. The results can be summarized as follows: (i) the acute and chronic invalidation of the CB(1) receptor resulted in an increase of behavioral habituation during the first exposure to an open field, indicative of enhanced acquisition of the task; (ii) CB(1)R(-/-) mice, but not rimonabant-treated animals, showed enhanced retention of the habituation task when re-tested 48 h and 1 week subsequent to the first exposure to the open field, respectively; (iii) the facilitation of retention of the habituation task in CB(1)R(-/-) mice was accompanied by a selective and site-specific increase in serotonin activity in hippocampus; and (iv) rimonabant-treated animals displayed 'antidepressant-like' neurochemical alterations of cerebral monoamines, that is, most parameters of monoaminergic activity were increased especially in dorsal striatum and hippocampus. Taken together, the present findings demonstrate that the genetic disruption of the CB(1) receptor gene can cause an improvement of behavioral habituation, which is considered to represent a form of 'non-associative' learning. Furthermore, our data support the assumption of a rimonabant-sensitive cannabinoid receptive site that is different from the 'classical' CB(1) receptor and which, under physiological conditions, might be involved in the inhibitory control of the acquisition but not retention of non-associative learning tasks.
Serotonin, CB1 -- physiology, CB1 -- genetics, Biogenic amines, Knockout, Neural Inhibition -- drug effects, Cerebral Cortex -- metabolism, Inbred Strains, Piperidines -- pharmacology, CB1-knockout, Mice, Inbred Strains, Psychophysiologic -- drug effects, Hippocampus, Statistics, Nonparametric, Association Learning -- physiology, Mice, Piperidines, Receptor, Cannabinoid, CB1, Hippocampus -- drug effects, Animals, Nonparametric, Hippocampus -- metabolism, CB1 -- antagonists & inhibitors, Habituation, Psychophysiologic, Cannabinoid, Pyrazoles -- pharmacology, Cerebral Cortex, Mice, Knockout, Analysis of Variance, Psychophysiologic -- physiology, Statistics, Association Learning, Neural Inhibition, Sciences bio-médicales et agricoles, Exploratory Behavior -- physiology, Exploratory Behavior -- drug effects, Serotonin -- metabolism, Neural Inhibition -- physiology, Cerebral Cortex -- drug effects, Exploratory Behavior, CB1 -- classification, Pyrazoles, Association Learning -- drug effects, Habituation, Rimonabant, Receptor
Serotonin, CB1 -- physiology, CB1 -- genetics, Biogenic amines, Knockout, Neural Inhibition -- drug effects, Cerebral Cortex -- metabolism, Inbred Strains, Piperidines -- pharmacology, CB1-knockout, Mice, Inbred Strains, Psychophysiologic -- drug effects, Hippocampus, Statistics, Nonparametric, Association Learning -- physiology, Mice, Piperidines, Receptor, Cannabinoid, CB1, Hippocampus -- drug effects, Animals, Nonparametric, Hippocampus -- metabolism, CB1 -- antagonists & inhibitors, Habituation, Psychophysiologic, Cannabinoid, Pyrazoles -- pharmacology, Cerebral Cortex, Mice, Knockout, Analysis of Variance, Psychophysiologic -- physiology, Statistics, Association Learning, Neural Inhibition, Sciences bio-médicales et agricoles, Exploratory Behavior -- physiology, Exploratory Behavior -- drug effects, Serotonin -- metabolism, Neural Inhibition -- physiology, Cerebral Cortex -- drug effects, Exploratory Behavior, CB1 -- classification, Pyrazoles, Association Learning -- drug effects, Habituation, Rimonabant, Receptor
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 11 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Average | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
