Firstly, olfactory association learning was used to determine the modulating effect of 5-HT4 receptor involvement in learning and long-term memory. Secondly, the effects of systemic injections of a 5-HT4 partial agonist and an antagonist on long-term potentiation (LTP) and depotentiation in the dentate gyrus (DG) were tested in freely moving rats. The modulating role of the 5-HT4 receptors was ...

Cardiac-valve regurgitation observed in Parkinson patients treated with the ergoline dopamine receptor agonist 8beta-methylthiomethyl-6-propylergoline (pergolide) has been associated with the agonist efficacy of the drug at 5-hydroxytryptamine(2B) (5-HT(2B)) receptors. 5-HT(2A) receptors may also play a role in pergolide-induced cardiac-valve regurgitation. We studied the pharmacological profil...

Varenicline, a widely used and successful smoking cessation agent, acts as a partial agonist at nicotinic acetylcholine receptors. Here, we explore the effects of varenicline at human and mouse 5-Hydroxytryptamine(3) (5-HT(3)) receptors. Application of varenicline to human 5-HT(3) receptors expressed in Xenopus laevis oocytes reveal it is almost a full agonist (R(max) = 80%) with an EC(50) (5.9...

Using a two-lever drug discrimination procedure, six rats were trained to discriminate 0.5 mg/kg of racemic 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) from saline. Once trained, the animals demonstrated a dose-related decrease in discriminative performance upon administration of lower doses of DOI (ED50 = 0.16 mg/kg). DOI-stimulus generalization occurred with the putative 5-HT2 agonist...