Sustained increase of alpha7 nicotinic receptors and choline-induced improvement of learning deficit in STOP knock-out mice.
Mice deficient in the microtubule stabilizing protein STOP (stable tubule only polypeptide) show synaptic plasticity anomalies in hippocampus, dopamine hyper-reactivity in the limbic system and severe behavioral deficits. Some of these disturbances are alleviated by long-term antipsychotic treatment. Therefore, this mouse line represents a pertinent model for some aspects of schizophrenia symptomatology. Numerous data support dysfunction of nicotinic neurotransmission in schizophrenia and epidemiological studies show increased tobacco use in schizophrenic patients, in whom nicotine has been reported to improve cognitive deficits and impairment in sensory gating. In this study, we examined potential alterations in cholinergic (ACh) and nicotinic components and functions in STOP mutant mice. STOP KO mice displayed no variation of the density of ACh esterase and beta2* nicotinic receptors (nAChRs), large reductions in the density of vesicular ACh transporter and alpha6* nAChRs and marked increases in the density of alpha7 nAChRs, in some brain areas. STOP KO mice were hypersensitive to the stimulating locomotor effect of nicotine and, interestingly, their impaired performance in learning the cued version of the water maze were improved by administration of the preferential alpha7 nAChR agonist choline. Altogether, our data show that the deletion of the ubiquitous STOP protein elicited restricted alterations in ACh components. They also suggest that nicotinic neurotransmission can be deficient in STOP KO mice and that mutant mice can represent a meaningful model to study some nicotinic dysfunctions and therapeutic treatments.
Bouvrais-Veret
Caroline
C
Inserm, U513, Laboratoire de Neurobiologie et Psychiatrie, Créteil, F-94000 France.
Weiss
Stéphanie
S
Andrieux
Annie
A
Schweitzer
Annie
A
McIntosh
J Michael
JM
Job
Didier
D
Giros
Bruno
B
Martres
Marie-Pascale
MP
D000110:Acetylcholinesterase / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001345:Autoradiography; D001522:Behavior, Animal; D002794:Choline / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000235:genetics*; D007859:Learning Disabilities / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000172:deficiency*; D009043:Motor Activity / Q000187:drug effects / Q000235:genetics; D018697:Nootropic Agents / Q000627:therapeutic use*; D011930:Reaction Time / Q000187:drug effects; D011978:Receptors, Nicotinic / Q000235:genetics / Q000378:metabolism*; D050494:Vesicular Acetylcholine Transport Proteins / Q000378:metabolism; D064569:alpha7 Nicotinic Acetylcholine Receptor
C579166:Chrna7 protein, mouse; D008869:Microtubule-Associated Proteins; C491893:Mtap6 protein, mouse; D018697:Nootropic Agents; D011978:Receptors, Nicotinic; C493460:Slc18a3 protein, mouse; D050494:Vesicular Acetylcholine Transport Proteins; D064569:alpha7 Nicotinic Acetylcholine Receptor; D000110:Acetylcholinesterase; D002794:Choline