title: Hippocampal and striatal M1-muscarinic acetylcholine receptors are down-regulated following bilateral vestibular loss in rats.
abstract: Permanent vestibular loss has detrimental effects on the hippocampus, resulting in a disruption to spatial learning and memory, hippocampal theta rhythm and place cell field spatial coherence. Little is known about the vestibular system-related hippocampal cholinergic transmission. Since the pharmacological blockade of muscarinic acetylcholine (ACh) receptors within the hippocampus produces deficits in learning and memory, we hypothesized that ACh receptors may at least partly support the integration of vestibular input. Consequently, we examined the expression of M1muscarinic ACh receptors in the hippocampus at 7 and 30 days following bilateral vestibular lesions (BVL) in rats using autoradiography. Animals were divided into sham (n = 12) and BVL (n = 11) groups. BVL animals received intratympanic injections of sodium arsanilate (30 mg/0.1 ml) under isoflurane anesthesia and sham animals received the same volume of saline. Analysis of the brain tissue revealed a significant reduction in the number of M1receptors throughout the hippocampus and striatum at 30 days (P ≤ 0.0001), but not at 7 days following BVL. This suggests that the changes in learning and memory seen following vestibular damage may be in part due to the loss of M1muscarinic receptors in the hippocampus and striatum. © 2016 Wiley Periodicals, Inc.
authors: Department of Pharmacology and Toxicology, Brain Health Research Centre University of Otago, Dunedin, New Zealand.
authors: Phillip
authors: P
authors: Aitken
authors: Normandie Univ, UNICAEN, INSERM, COMETE, CHU Caen, 14000 Caen, France.
authors: Alice
authors: A
authors: Benoit
authors: Department of Pharmacology and Toxicology, Brain Health Research Centre University of Otago, Dunedin, New Zealand.|Brain Research New Zealand Centre of Research Excellence, New Zealand.
authors: Yiwen
authors: Y
authors: Zheng
authors: Normandie Univ, UNICAEN, INSERM, COMETE, CHU Caen, 14000 Caen, France.
authors: Bruno
authors: B
authors: Philoxene
authors: Normandie Univ, UNICAEN, INSERM, COMETE, CHU Caen, 14000 Caen, France.
authors: Anne
authors: A
authors: Le Gall
authors: Normandie Univ, UNICAEN, INSERM, COMETE, CHU Caen, 14000 Caen, France.
authors: Pierre
authors: P
authors: Denise
authors: Normandie Univ, UNICAEN, INSERM, COMETE, CHU Caen, 14000 Caen, France.
authors: Stephane
authors: S
authors: Besnard
authors: Department of Pharmacology and Toxicology, Brain Health Research Centre University of Otago, Dunedin, New Zealand.|Brain Research New Zealand Centre of Research Excellence, New Zealand.
authors: Paul F
authors: PF
authors: Smith
mesh_terms: D000818:Animals; D001147:Arsanilic Acid; D001345:Autoradiography; D000071699:Bilateral Vestibulopathy / Q000378:metabolism* / Q000473:pathology; D003342:Corpus Striatum / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D015536:Down-Regulation; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D008297:Male; D018727:Muscarinic Antagonists; D010890:Pirenzepine; D017208:Rats, Wistar; D043643:Receptor, Muscarinic M1 / Q000378:metabolism*; D013997:Time Factors; D014316:Tritium
chemical_list: D018727:Muscarinic Antagonists; D043643:Receptor, Muscarinic M1; D014316:Tritium; D010890:Pirenzepine; D001147:Arsanilic Acid
keywords: autoradiography; bilateral vestibular lesions; caudate putamen; hippocampus; spatial memory