Y Tizabi1, R L Copeland, R Brus, R M Kostrzewa. 1. Department of Pharmacology, College of Medicine, Howard University, 520W Street N.W., Washington, DC 20059, USA. ytizabi@howard.edu
Abstract
RATIONALE AND OBJECTIVES: Because of known and imputed roles of dopaminergic and nicotinic cholinergic systems in a variety of neurological and neuropsychiatric disorders, combined neurochemical and behavioral methods assessments were made to study the intermodulatory roles of these neurochemical systems. METHODS: Rats were treated daily during postnatal ontogeny with the dopamine D2/D) agonist, quinpirole (QNP) HCl (1.0 mg/kg/day), for the first 3 weeks from birth. This priming process replicated previous findings of behavioral sensitization, manifested as hyperlocomotion, increased paw treading with jumping, and increased yawning. RESULTS: All effects were partially or totally blocked by acute treatment with nicotine (0.3 mg/kg, i.p.). The effects of nicotine, in turn, were partially or totally blocked by the nicotinic antagonist, mecamylamine (1.0 mg/kg, i.p.). In concert with these behavioral actions, QNP-primed rats displayed greater binding of [3H]cytisine in midbrain and cerebellum and greater [125I]alpha-bungarotoxin binding in hippocampus and striatum. CONCLUSIONS: Accordingly, these selective ligands for alpha4beta2 and alpha7 nicotinic receptors, respectively, demonstrate that nicotinic receptors are altered by dopamine D2/D3 agonist treatment of rats with primed dopamine receptors. We propose that nicotinic agonists may have a therapeutic benefit in behavioral disorders brought about by central dopaminergic imbalance.
RATIONALE AND OBJECTIVES: Because of known and imputed roles of dopaminergic and nicotinic cholinergic systems in a variety of neurological and neuropsychiatric disorders, combined neurochemical and behavioral methods assessments were made to study the intermodulatory roles of these neurochemical systems. METHODS:Rats were treated daily during postnatal ontogeny with the dopamine D2/D) agonist, quinpirole (QNP) HCl (1.0 mg/kg/day), for the first 3 weeks from birth. This priming process replicated previous findings of behavioral sensitization, manifested as hyperlocomotion, increased paw treading with jumping, and increased yawning. RESULTS: All effects were partially or totally blocked by acute treatment with nicotine (0.3 mg/kg, i.p.). The effects of nicotine, in turn, were partially or totally blocked by the nicotinic antagonist, mecamylamine (1.0 mg/kg, i.p.). In concert with these behavioral actions, QNP-primed rats displayed greater binding of [3H]cytisine in midbrain and cerebellum and greater [125I]alpha-bungarotoxin binding in hippocampus and striatum. CONCLUSIONS: Accordingly, these selective ligands for alpha4beta2 and alpha7 nicotinic receptors, respectively, demonstrate that nicotinic receptors are altered by dopamine D2/D3 agonist treatment of rats with primed dopamine receptors. We propose that nicotinic agonists may have a therapeutic benefit in behavioral disorders brought about by central dopaminergic imbalance.
Authors: Richard M Kostrzewa; Karolina Wydra; Malgorzata Filip; Cynthia A Crawford; Sanders A McDougall; Russell W Brown; Dasiel O Borroto-Escuela; Kjell Fuxe; Raul R Gainetdinov Journal: J Pharmacol Exp Ther Date: 2018-06-19 Impact factor: 4.030
Authors: Marla K Perna; Zackary A Cope; Amanda M Maple; Ian D Longacre; Jennifer A Correll; Russell W Brown Journal: Psychopharmacology (Berl) Date: 2008-06-12 Impact factor: 4.530