title: Cholinergic immunotoxin 192 IgG-SAPORIN alters subicular theta-gamma activity and impairs spatial learning in rats.
abstract: Subiculum is an important structure of hippocampal formation and is a part of intra hippocampal network involved in spatial information processing. However, relatively very few studies are available in literature demonstrating the explicit role of subiculum in spatial information processing. The present study investigated the cholinergic modulation of subicular theta-gamma activity on spatial learning and memory functions in rats. The cholinergic projections to ventral subiculum were selectively eliminated using 192 IgG-SAPORIN. Eliminations of cholinergic inputs to ventral subiculum significantly reduced the subicular theta and enhanced the gamma activity during active wake and REM sleep states. In addition, the spatial learning was severely impaired following cholinergic elimination of ventral subiculum. The ChAT immunocytochemical studies showed sparse distribution of cholinergic fibers in the ventral subiculum confirming the cholinergic elimination to ventral subiculum. Cholinotoxic infusions to ventral subiculum did not alter the hippocampal cholinergic innervations and retained the hippocampal theta and gamma activities. The present findings support that cholinergic modulation of subicular theta-gamma oscillations is crucial for spatial information processing.
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: Shweta
authors.initials: S
authors.lastname: Rastogi
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: Sumithra
authors.initials: S
authors.lastname: Unni
authors.affiliation: Forensic and Medical Systems, Axxonet Systems Technologies Pvt. Ltd., Bangalore, India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: T Rao
authors.initials: TR
authors.lastname: Laxmi
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India. Electronic address: bindu.nimhans@gmail.com.
authors.forename: Bindu M
authors.initials: BM
authors.lastname: Kutty
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D002799:Cholinergic Fibers / Q000187:drug effects / Q000378:metabolism; D065818:Gamma Rhythm / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D000922:Immunotoxins / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D054789:Ribosome Inactivating Proteins, Type 1 / Q000494:pharmacology*; D000076985:Saporins; D065853:Spatial Learning / Q000187:drug effects*; D013826:Theta Rhythm / Q000187:drug effects*
chemical_list: C085696:192 IgG-saporin; D000911:Antibodies, Monoclonal; D000922:Immunotoxins; D054789:Ribosome Inactivating Proteins, Type 1; D002795:Choline O-Acetyltransferase; D000076985:Saporins
keywords: Cholinergic projections; Cholinotoxin; REM sleep; Spatial memory; Theta–gamma oscillations; Ventral subiculum