Disrupted visceral feedback reduces locomotor activity and influences background contextual fear conditioning in C57BL/6JOlaHsd mice

The present experiments were designed to study fear conditioning as an emotional learning task with disrupted visceral feedback. For that purpose we used the peripherally acting β1-adrenoceptor blocker atenolol and studied its effects on the behavior of male C57BL/6JOlaHsd mice in an exploration-rel...

Full description

Saved in:
Bibliographic Details
Published in:Behavioural brain research 2007-08, Vol.182 (1), p.109-118
Main Authors: Janitzky, K., Linke, R., Yilmazer-Hanke, D.M., Grecksch, G., Schwegler, H.
Format: Article
Language:English
Subjects:
Adrenergic beta-Antagonists - pharmacology
alpha-Synuclein - deficiency
Analysis of Variance
Animals
Anxiety disorder
Atenolol - pharmacology
Behavior, Animal
Beta-adrenergic blocker
Beta-adrenoceptor
Blood Proteins - deficiency
Conditioning, Operant - drug effects
Conditioning, Operant - physiology
Contextual fear
Dose-Response Relationship, Drug
Fear - drug effects
Fear - physiology
Fear conditioning
Feedback - drug effects
Feedback - physiology
Freezing Reaction, Cataleptic - drug effects
Freezing Reaction, Cataleptic - physiology
Male
Mice
Mice, Inbred C57BL
Mice, Knockout
Motor Activity - drug effects
Motor Activity - physiology
Open field
Social phobia
Sympathetic nervous system
Visceral feedback
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The present experiments were designed to study fear conditioning as an emotional learning task with disrupted visceral feedback. For that purpose we used the peripherally acting β1-adrenoceptor blocker atenolol and studied its effects on the behavior of male C57BL/6JOlaHsd mice in an exploration-related test and during fear-conditioning. In the first experiment, we treated mice with saline or different doses of the β1-adrenergic blocker atenolol (5 mg/kg and 20 mg/kg body weight i.p.) 30 min before behavioral testing in a motility box. Only the high but not the low dose of atenolol led to a reduction of locomotor activity ( p < 0.02). Factors known to be related to emotionality (rearing, area preference) were unaffected. In a second experiment, saline- and atenolol-treated mice (same dosages and mode of application) were trained for auditory fear conditioning, and 24 h later they were retested in the same environment. We found differences between the effects of atenolol upon contextual- and cue-fear conditioning. Animals treated with 20 mg/kg BW doses of atenolol showed significantly decreased background contextual fear compared to saline-treated control animals. In contrast, no differences were found during CS presentation in the conditioning context between atenolol-treated animals and saline-treated controls, independent from a paired or an unpaired conditioning paradigm. Thus, the blockade of peripheral β1-adrenoceptors by atenolol may have disrupted the positive feedback to the central nervous system via visceral afferents resulting in a decreased locomotor activity and background contextual fear.
ISSN:0166-4328
1872-7549
DOI:10.1016/j.bbr.2007.05.015