Effect of histamine H1 and H2 receptor antagonists, microinjected into cerebellar vermis, on emotional memory consolidation in mice

Author(s)

A.C.L. Gianlorenço ^[1] ; K.R. Serafim ^[2] ; A. Canto-de-Souza ^{[3, 4, 5]} ; R. Mattioli ^[2]

Affiliation

^[1] Universidade Federal de São Carlos. Centro de Ciências Biológicas e da Saúde. Departamento de Fisioterapia - Brasil

^[2] Univ Fed Sao Carlos, Lab Neurociencias, Dept Fisioterapia, Ctr Ciencias Biol & Saude, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Fed Sao Carlos, Lab Psicol Aprendizagem, Dept Psicol, Ctr Educ & Ciencias Humanas, BR-13565905 Sao Carlos, SP - Brazil

^[4] Univ Fed Sao Carlos, Programa Posgrad Ciencias Fisiol, BR-13565905 Sao Carlos, SP - Brazil

^[5] Univ Sao Paulo, Inst Neurociencias & Comportamento, BR-14049 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Brazilian Journal of Medical and Biological Research; v. 47, n. 2, p. 135-143, 2014-02-00.

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. (AU)

• FAPESP's process: 09/15836-1 - Influence of cerebellar histaminergic neural system on emotional memory in mice
• Grantee: Anna Carolyna Lepesteur Gianlorenço
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/17496-3 - Influence of the cerebellar histaminergic system on emotional memory in mice
• Grantee: Rosana Mattioli
• Support Opportunities: Regular Research Grants