title: α7 neuronal nicotinic receptor agonist (TC-7020) reverses increased striatal dopamine release during acoustic PPI testing in a transgenic mouse model of schizophrenia.
abstract: Genetic and post mortem evidence has implicated the α7 neuronal nicotinic receptor (NNR) in the etiology of schizophrenia and related disorders. In schizophrenia, enhanced subcortical dopamine (DA) correlates with positive and cognitive of the disease, including impairments in sensorimotor gating. We measured the levels of extracellular DA and DA metabolites during an acoustic test session of prepulse inhibition (PPI) of the startle response, a measure of sensorimotor gating, by microdialysis and HPLC-EC in a transgenic mouse model of schizophrenia. In th-fgfr1(tk-) mice, blockade of fibroblast growth factor receptor 1 (FGFR1) signaling during development in catecholaminergic neurons results in reduced size and density of midbrain DA neurons of the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA). These mice displayed reduced PPI and enhanced startle response relative to control mice as well as a potentiation of DA release in the dorsal striatum during a 30 minute PPI test session. Acute administration of a partial α7 NNR agonist TC-7020 (1.0 mg/kg) normalized PPI and startle deficits and attenuated increases of DA release during acoustic PPI testing. These results provide direct evidence of elevated striatal dopaminergic transmission with impaired sensorimotor gating that may underlie cognitive and positive symptoms and motor deficits in schizophrenia and related disorders. Also, systemic targeting of alpha7 NNRs may ameliorate these deficits by functionally suppressing striatal DA activity.
authors.affiliation: Department of Pathology and Anatomical Sciences, SUNY, Buffalo, NY 14214, USA.
authors.forename: A
authors.initials: A
authors.lastname: Kucinski
authors.forename: C
authors.initials: C
authors.lastname: Syposs
authors.forename: S
authors.initials: S
authors.lastname: Wersinger
authors.forename: M
authors.initials: M
authors.lastname: Bencherif
authors.forename: M K
authors.initials: MK
authors.lastname: Stachowiak
authors.forename: E K
authors.initials: EK
authors.lastname: Stachowiak
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006719:Homovanillic Acid / Q000378:metabolism; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D017551:Microdialysis / Q000379:methods; D009433:Neural Inhibition / Q000187:drug effects* / Q000235:genetics; D018722:Nicotinic Agonists / Q000494:pharmacology; D011812:Quinuclidines / Q000494:pharmacology; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000172:deficiency / Q000235:genetics; D013216:Reflex, Startle / Q000187:drug effects / Q000235:genetics; D012559:Schizophrenia / Q000188:drug therapy* / Q000235:genetics / Q000503:physiopathology*; D055139:Sensory Gating / Q000187:drug effects* / Q000235:genetics; D013876:Thiophenes / Q000494:pharmacology
chemical_list: C573434:5-methyl-N-(2-(pyridin-3-ylmethyl)-1-azabicyclo(2.2.2)oct-3-yl)thiophene-2-carboxamide; D018722:Nicotinic Agonists; D011812:Quinuclidines; D013876:Thiophenes; D015102:3,4-Dihydroxyphenylacetic Acid; D051496:Receptor, Fibroblast Growth Factor, Type 1; D004298:Dopamine; D006719:Homovanillic Acid