Intraseptal infusions of 8-OH-DPAT in the rat impairs water-maze performances: effects on memory or anxiety?

In the rat, 5-HT1A receptors are found on medial septal cholinergic neurons . The effects of intraseptal infusions of the 5-HT1A receptor agonist 8-OH- DPAT (8-hydroxy-2-(di-n-propyl-amino)-tetralin) were assessed on reference memory performances in a water maze. Compared with vehicle infusions, 0.5 a nd 4 mu g of 8-OH-DPAT significantly impaired (but did not prevent) acquisi tion of the task and probe-trial performances. The results suggest that act ivation of 5-TH1A receptors in the (medial) septal area impairs spatial lea rning, perhaps directly by reducing the hippocampal cholinergic;onus, or in directly by an effect on anxiety. (C) 2000 Elsevier Science Ireland Ltd. Al l rights reserved.