title: Effect of histamine H1 and H2 receptor antagonists, microinjected into cerebellar vermis, on emotional memory consolidation in mice.
abstract: This study investigated the effects of histamine H1 or H2 receptor antagonists on emotional memory consolidation in mice submitted to the elevated plus maze (EPM). The cerebellar vermis of male mice (Swiss albino) was implanted using a cannula guide. Three days after recovery, behavioral tests were performed in the EPM on 2 consecutive days (T1 and T2). Immediately after exposure to the EPM (T1), animals received a microinjection of saline (SAL) or the H1 antagonist chlorpheniramine (CPA; 0.016, 0.052, or 0.16 nmol/0.1 µL) in Experiment 1, and SAL or the H2 antagonist ranitidine (RA; 0.57, 2.85, or 5.7 nmol/0.1 µL) in Experiment 2. Twenty-four hours later, mice were reexposed to the EPM (T2) under the same experimental conditions but they did not receive any injection. Data were analyzed using one-way ANOVA and the Duncan test. In Experiment 1, mice microinjected with SAL and with CPA entered the open arms less often (%OAE) and spent less time in the open arms (%OAT) in T2, and there was no difference among groups. The results of Experiment 2 demonstrated that the values of %OAE and %OAT in T2 were lower compared to T1 for the groups that were microinjected with SAL and 2.85 nmol/0.1 µL RA. However, when animals were microinjected with 5.7 nmol/0.1 µL RA, they did not show a reduction in %OAE and %OAT. These results demonstrate that CPA did not affect behavior at the doses used in this study, while 5.7 nmol/0.1 µL RA induced impairment of memory consolidation in the EPM.
authors: Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São CarlosSP, Brasil, Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP, Brasil.
authors: A C L
authors: AC
authors: Gianlorenço
authors: Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São CarlosSP, Brasil, Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP, Brasil.
authors: K R
authors: KR
authors: Serafim
authors: Laboratório de Psicologia da Aprendizagem, Departamento de Psicologia, Centro de Educação e Ciências Humanas, Universidade Federal de São Carlos, São CarlosSP, Brasil, Laboratório de Psicologia da Aprendizagem, Departamento de Psicologia, Centro de Educação e Ciências Humanas, Universidade Federal de São Carlos, São Carlos, SP, Brasil.
authors: A
authors: A
authors: Canto-de-Souza
authors: Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São CarlosSP, Brasil, Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP, Brasil.
authors: R
authors: R
authors: Mattioli
mesh_terms: D000818:Animals; D065814:Cerebellar Vermis / Q000187:drug effects*; D002744:Chlorpheniramine / Q000494:pharmacology*; D004644:Emotions / Q000187:drug effects*; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D008845:Microinjections; D011899:Ranitidine / Q000494:pharmacology*
chemical_list: D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D002744:Chlorpheniramine; D011899:Ranitidine