CB1 Cannabinoid Receptors Mediate Cognitive Deficits and Structural Plasticity Changes During Nicotine Withdrawal.

Abstract

BACKGROUND:

Tobacco withdrawal is associated with deficits in cognitive function, including attention, working memory, and episodic memory. Understanding the neurobiological mechanisms involved in these effects is crucial because cognitive deficits during nicotine withdrawal may predict relapse in humans.

METHODS:

We investigated in mice the role of CB1 cannabinoid receptors (CB1Rs) in memory impairment and spine density changes induced by nicotine withdrawal precipitated by the nicotinic antagonist mecamylamine. Drugs acting on the endocannabinoid system and genetically modified mice were used.

RESULTS:

Memory impairment during nicotine withdrawal was blocked by the CB1R antagonist rimonabant or the genetic deletion of CB1R in forebrain gamma-aminobutyric acidergic (GABAergic) neurons (GABA-CB1R). An increase of 2-arachidonoylglycerol (2-AG), but not anandamide, was observed during nicotine withdrawal. The selective inhibitor of 2-AG biosynthesis O7460 abolished cognitive deficits of nicotine abstinence, whereas the inhibitor of 2-AG enzymatic degradation JZL184 did not produce any effect in cognitive impairment. Moreover, memory impairment was prevented by the selective mammalian target of rapamycin inhibitor temsirolimus and the protein synthesis inhibitor anisomycin. Mature dendritic spines on CA1 pyramidal hippocampal neurons decreased 4 days after the precipitation of nicotine withdrawal, when the cognitive deficits were still present. Indeed, a correlation between memory performance and mature spine density was found. Interestingly, these structural plasticity alterations were normalized in GABA-CB1R conditional knockout mice and after subchronic treatment with rimonabant.

CONCLUSIONS:

These findings underline the interest of CB1R as a target to improve cognitive performance during early nicotine withdrawal. Cognitive deficits in early abstinence are associated with increased relapse risk.

• Authors: Rocio Saravia, África Flores, Ainhoa Plaza-Zabala, Arnau Busquets-Garcia, Antoni Pastor, Rafael de la Torre, Vincenzo Di Marzo, Giovanni Marsicano, Andrés Ozaita, Rafael Maldonado, Fernando Berrendero
• Journal: Biological psychiatry (Biol Psychiatry) Vol. 81 Issue 7 Pg. 625-634 (04 01 2017) ISSN: 1873-2402 [Electronic] United States
• PMID: 27737762 (Publication Type: Journal Article)
• Copyright: Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Chemical References

• Arachidonic Acids
• Cannabinoid Receptor Antagonists
• Endocannabinoids
• Glycerides
• Piperidines
• Polyunsaturated Alkamides
• Pyrazoles
• Receptor, Cannabinoid, CB1
• Receptors, GABA
• Nicotine
• glyceryl 2-arachidonate
• Rimonabant
• anandamide

Topics

• Animals
• Arachidonic Acids (metabolism)
• Brain (drug effects, metabolism, physiology)
• Cannabinoid Receptor Antagonists (administration & dosage)
• Endocannabinoids (metabolism)
• GABAergic Neurons (drug effects, physiology)
• Glycerides (metabolism)
• Male
• Memory (drug effects, physiology)
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Neuronal Plasticity (drug effects)
• Nicotine (administration & dosage)
• Piperidines (administration & dosage)
• Polyunsaturated Alkamides (metabolism)
• Pyramidal Cells (drug effects, physiology)
• Pyrazoles (administration & dosage)
• Receptor, Cannabinoid, CB1 (antagonists & inhibitors, genetics, physiology)
• Receptors, GABA (genetics, physiology)
• Recognition, Psychology (drug effects, physiology)
• Rimonabant
• Substance Withdrawal Syndrome (metabolism, physiopathology)