title: Effects of 7-nitroindazole, a selective neural nitric oxide synthase inhibitor, on context-shock associative learning in a two-process contextual fear conditioning paradigm.
abstract: Nitric oxide (NO) is an important retrograde neuronal intracellular messenger which plays an important role in synaptic plasticity and is involved in learning and memory. However, evidence that NO is particularly important for the acquisition of contextual fear conditioning is mixed. Also, little is known about at which stages of the contextual fear conditioning does NO make its contribution. In the present study, we used 7-nitroindazole to temporarily inhibit neural nitric oxide synthase at either the pre-exposure stage or conditioning stage in a two-process paradigm and examined the potential contribution that NO makes to the contextually conditioned fear. Results showed that the expression of contextual fear memory was significantly impaired in rats treated with 7-nitroindazole (30mg/kg, i.p.) prior to the pairing of context-shock (p=0.034, n=8), but not after the conditioning phase (p=0.846, n=8). In addition, the expression of contextual fear memory and reconsolidation was not significantly impaired by 7-nitroindazole administered prior to the context pre-exposure stage or prior to another context-shock learning. These findings suggest that NO is specifically involved in the acquisition but not the consolidation, retrieval or reconsolidation of contextual fear memory.
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, Chongqing, China; Faculty of Psychology, Southwest University, Chongqing, China. Electronic address: whchen@swu.edu.cn.
authors.forename: Weihai
authors.initials: W
authors.lastname: Chen
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, Chongqing, China; Faculty of Psychology, Southwest University, Chongqing, China.
authors.forename: Minmin
authors.initials: M
authors.lastname: Yan
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, Chongqing, China; Faculty of Psychology, Southwest University, Chongqing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, Chongqing, China; Faculty of Psychology, Southwest University, Chongqing, China.
authors.forename: Xiaqing
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, Chongqing, China; Faculty of Psychology, Southwest University, Chongqing, China. Electronic address: yuanjiajin168@126.com.
authors.forename: Jiajin
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, Chongqing, China; Faculty of Psychology, Southwest University, Chongqing, China; Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE 68588-0308, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D000818:Animals; D001245:Association Learning / Q000187:drug effects*; D003214:Conditioning, Classical / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D005239:Fear / Q000187:drug effects*; D007191:Indazoles / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004791:Enzyme Inhibitors; D007191:Indazoles; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; C080122:7-nitroindazole
keywords: 7-Nitroindazole; Nitric oxide; Nitric oxide synthase; Two-process contextual fear conditioning