Alpha2C-adrenoceptor overexpression disrupts execution of spatial and non-spatial search patterns.
We investigated the role of alpha2C-adrenoceptors in the modulation of spatial and non-spatial navigation behaviour. Alpha2C-adrenoceptor overexpressing mice developed an ineffective thigmotaxic search pattern characterized by swimming close to the pool walls during both spatial and non-spatial water maze training. A subtype-non-selective alpha2-adrenoceptor antagonist, atipamezole (1000 microg/kg, s.c.), fully reversed this impairment in their search strategy. Withdrawal of atipamezole at the end of spatial training resulted in an immediate disruption of the search pattern in alpha2C-adrenoceptor overexpressing mice. The swimming pattern of alpha2C-adrenoceptor overexpressing mice during a five day free swimming period was normal, when no cognitive component was required. Diazepam (0.3 and 1.0 mg/kg, i.p.), neither improved the accuracy in finding the platform nor decreased thigmotaxis. These results suggest that alpha2C-adrenoceptors may modulate the execution of complex navigation patterns.
Björklund
M
M
Department of Neurology and Neuroscience, University of Kuopio, Finland.
Sirviö
J
J
Sallinen
J
J
Scheinin
M
M
Kobilka
B K
BK
Riekkinen
P
P
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D004924:Escape Reaction / Q000187:drug effects; D005260:Female; D007093:Imidazoles / Q000494:pharmacology; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008815:Mice, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D013037:Spatial Behavior / Q000187:drug effects / Q000502:physiology*; D013550:Swimming
D000317:Adrenergic alpha-Antagonists; D014151:Anti-Anxiety Agents; D007093:Imidazoles; D011942:Receptors, Adrenergic, alpha; C050701:atipamezole; D003975:Diazepam