Interaction of neural histaminergic and cholinergic systems in the amygdala: emotional behavior modulation

• Grant number: 13/17242-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2013
• End date: April 30, 2014
• Field of knowledge: Humanities - Psychology - Physiological Psychology
• Principal Investigator: Kelly Regina Serafim
• Grantee: Beatriz Alampi Cazarim
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

This project aims to investigate the interaction between histaminergic and cholinergic neural systems in the amygdala of mice in emotional memory retrieval, using the elevated plus maze (EPM) test. Guide cannulae will be bilaterally implanted in the amygdala under stereotaxic surgery. Four days after surgical recovery, the animals will receive intra-amygdala infusions of saline (SAL) or 0.16 nmol/0.1¼l Chlorpheniramine (CPA, an H1 receptor antagonist), and infusions of the agonist cholinergic PNU 282987 (0.3¼g/0.1¼l), five minutes after CPA infusion. Tests will be performed on 2 consecutive days, designated T1 and T2. In T1, the animals will be exposed to the EPM for 5 minutes; Before T2, twenty four hours later, mice will receive the pharmacological treatment and will be subjected to the EPM test. The animals will be randomly assigned to four groups based on drug treatment: SAL-SAL (n=10); SAL+CPA (n=10); CPA+PNU (n=10); PNU+SAL (n=10). Behavioral parameters will include the following: frequencies of open and enclosed arm entries (OAE and EAE), total time spent in open arms (OAT), total time spent in enclosed arms (EAT), and total time spent in the central area (CT). These data were used to calculate the percentages of OAE [%OAE; (OAE/TE) × 100] and OAT [%OAT; (OAT/300) × 100]. An increase in open arm avoidance will be used as a measure of learning and memory evaluated by T1/T2 protocol. The data will be analyzed using two-way repeated measures ANOVA (factor 1: treatment; factor 2: trial). Significant F values will be followed by post hoc Duncan's multiple range tests.