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Role of α 2C ‐adrenoceptor subtype in spatial working memory as revealed by mice with targeted disruption of the α 2C ‐adrenoceptor gene
Author(s) -
Tanila H.,
Mustonen K.,
Sallinen J.,
Scheinin M.,
Riekkinen P.
Publication year - 1999
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.1999.00464.x
Subject(s) - agonist , dexmedetomidine , medicine , endocrinology , working memory , adrenergic receptor , receptor , biology , chemistry , neuroscience , pharmacology , cognition , sedation
The role of the α 2C ‐adrenoceptor subtype in mediating the beneficial effect of α 2 ‐adrenoceptor agonists on spatial working memory was studied in adult mice with targeted inactivation of the α 2C ‐receptor gene (KO) and their wild‐type controls (WT). A delayed alternation task was run in a T‐maze with mixed delays varying from 20 s to 120 s. Dexmedetomidine, a specific but subtype non‐selective α 2 ‐adrenoceptor agonist, dose‐dependently decreased the total number of errors. The effect was strongest at the dose of 5 μg/kg (s.c.), and was observed similarly in KO and WT mice. KO mice performed inferior to WT mice due to a higher number of perseverative errors. Dexmedetomidine slowed initiation of the motor response in the start phase at lower doses in WT mice than in KO mice but no such difference was observed in the return phase of the task, suggesting involvement of α 2C ‐adrenoceptors in the cognitive aspect of response preparation or in response sequence initiation. According to these findings, enhancement of spatial working memory is best achieved with α 2 ‐adrenoceptor agonists which have neither agonistic nor antagonistic effects at the α 2C ‐adrenoceptor subtype.