Abstract |
This study investigated the role of H₁ and H₂ receptors in anxiety and the retrieval of emotional memory using a Trial 1/Trial 2 (T1/T2) protocol in an elevated plus-maze (EPM). Tests were performed on 2 consecutive days, designated T1 and T2. Before T1, the mice received intraperitoneal injections of saline (SAL), 20 mg/kg zolantidine (ZOL, an H2 receptor antagonist), or 8.0 or 16 mg/kg chlorpheniramine (CPA, an H1 receptor antagonist). After 40 min, they were subjected to the EPM test. In T2 (24 h later), each group was subdivided into two additional groups, and the animals from each group were re-injected with SAL or one of the drugs. In T1, the Student t-test showed no difference between the SAL and ZOL or 8 mg/kg CPA groups with respect to the percentages of open arm entries (%OAE) and open arm time (%OAT). However, administration of CPA at the highest dose of 16 mg/kg decreased %OAE and %OAT, but not locomotor activity, indicating anxiogenic-like behavior. Emotional memory, as revealed by a reduction in open arm exploration between the two trials, was observed in all experimental groups, indicating that ZOL and 8 mg/kg CPA did not affect emotional memory, whereas CPA at the highest dose affected acquisition and consolidation, but not retrieval of memory. Taken together, these results suggest that H₁ receptor, but not H₂, is implicated in anxiety-like behavior and in emotional memory acquisition and consolidation deficits in mice subjected to EPM testing.
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Authors | K R Serafim, M S Kishi, A Canto-de-Souza, R Mattioli |
Journal | Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas
(Braz J Med Biol Res)
Vol. 46
Issue 5
Pg. 440-6
(May 2013)
ISSN: 1414-431X [Electronic] Brazil |
PMID | 23598647
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Benzothiazoles
- Histamine H1 Antagonists
- Histamine H2 Antagonists
- Phenoxypropanolamines
- Piperidines
- Receptors, Histamine H1
- Chlorpheniramine
- zolantidine
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Topics |
- Animals
- Anxiety
(chemically induced)
- Benzothiazoles
(pharmacology)
- Chlorpheniramine
(pharmacology)
- Histamine H1 Antagonists
(pharmacology)
- Histamine H2 Antagonists
(pharmacology)
- Male
- Maze Learning
- Memory Disorders
(chemically induced)
- Mice
- Microinjections
- Phenoxypropanolamines
(pharmacology)
- Piperidines
(pharmacology)
- Receptors, Histamine H1
(drug effects)
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