Effects of alpha-adrenoceptor agonists and antagonists in a maze-exploration model of ?fear?-motivated behaviour
- 1 January 1984
- journal article
- research article
- Published by Springer Nature in Naunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmakologie
- Vol. 327 (1), 1-5
- https://doi.org/10.1007/bf00504983
Abstract
An elevated X-maze with alternating open and enclosed arms was investigated as a model for the study of fear-induced behaviour. As predicted, the anxiolytics diazepam and amylobarbitone increased, and the putative anxiogenics ACTH and picrotoxin decreased the proportion of open arm entries. The α1-adrenoceptor agonists phenylephrine and ST587, and the α2-adrenoceptor antagonists idazoxan, piperoxane, RS-21361 and yohimbine decreased relative open-arm entries, thus resembling the putative anxiogenics. On the other hand, azepexole, clonidine and guanabenz, agonists at α2-adrenoceptors, and the α1-adrenoceptor antagonists prazosin and thymoxamine, enhanced the proportion of open arm entries at low doses, suggesting anxiolytic-like properties. A paradoxical fall in open arm entries occurred with these agents at higher doses. These results provide further evidence for the involvement of noradrenergic systems in ‘fear’-motivated behaviour.Keywords
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