The NK-3 tachykinin agonist senktide elicits yawning and chewing mouth movements following subcutaneous administration in the rat. Evidence for cholinergic mediation

Abstract

The selective NK-3 tachykinin receptor agonist senktide elicited yawning, chewing mouth movements and sexual arousal following subcutaneous administration (0.1-1.0 mg/kg) in the rat. These responses were not significantly affected by the dopamine antagonist haloperidol (0.03 mg/kg) or by 6-hydroxydopamine lesions of the nigrostriatal projection. In contrast, the behaviours were markedly attenuated by the peripheral and central muscarinic antagonist scopolamine (1 mg/kg), but not by the peripheral muscarinic antagonist N-methylscopolamine (1 mg/kg). These findings suggest that stimulation of NK-3 receptors produces yawning, chewing and sexual arousal by directly activating central cholinergic neurons.

Neurokinin3 receptor activation potentiates the psychomotor and nucleus accumbens dopamine response to cocaine, but not its place conditioning effects

“…The doses of senktide used in the present study were chosen on the basis of evidence from other studies (Stoessl et al ., 1988a,b) showing behavioural activity of the compound in the range of 0.1–1.0 mg/kg after s.c. administration. Senktide is a ligand with both high selectivity and equally high affinity for NK 3 ‐Rs of different species (Laufer et al ., 1986).…”

Comparative behavioural profile of centrally administered tachykinin NK1, NK2 and NK3 receptor agonists in the guinea‐pig

“…(Stoessl et al, 1988a;Picard et al, 1994). However, intracisternal or subcutaneous administration of senktide in the rat has been also reported to produce a syndrome mediated by endogenous 5-HT including forepaw treading and hindlimb splaying (Wormser et al, 1986;Stoessl et al, 1987) and acetylcholinemediated behaviours, yawning, chewing mouth movements and sexual arousal (Stoessl et al, 1988b (Dam & Quirion, 1986;Stoessl et al, 1991). Surprisingly, in our experiments, only the NKI receptor agonists, when administered centrally to conscious freely moving guinea-pigs, lead to enhanced locomotion, the NK3 receptor agonist senktide being inactive.…”