Intra-raphe neurokinin-induced hyperactivity: effects of 5,7-dihydroxytryptamine lesions.
Rats were implanted with cannulae in the median raphe nucleus (MR). 5,7-Dihydroxytryptamine (5,7-DHT) or vehicle was infused either directly through the MR cannula, or bilaterally into the medial forebrain bundle (MFB). The MR 5,7-DHT lesions completely blocked the hyperactivity elicited by injections into the MR of the neurokinin (NK) 3 agonists, DiMe-C7 and senktide, and the NK-2 agonist, neurokinin A. In contrast, the MFB 5,7-DHT lesions did not affect the locomotor hyperactivity produced by intra-MR administration of DiMe-C7 and senktide, but appeared to attenuate the effects of NKA. The data indicate that intra-raphe neurokinin-induced hyperactivity is mediated by 5-HT neurons, and that 5-HT projections to the forebrain may be involved in the behavioral activation induced by intra-raphe neurokinin A administration, but not that induced by intra-MR NK-3 agonists.
Paris
J M
JM
Department of Pharmacology, Loyola University Medical Center, Maywood, IL 60153.
Mitsushio
H
H
Lorens
S A
SA
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D004102:Dihydroxytryptamines / Q000494:pharmacology*; D008297:Male; D008474:Medial Forebrain Bundle / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009043:Motor Activity / Q000187:drug effects*; D009434:Neural Pathways / Q000502:physiology*; D015288:Neurokinin A / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D011903:Raphe Nuclei / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology
D002395:Catecholamines; D004102:Dihydroxytryptamines; D010446:Peptide Fragments; C054724:senktide; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D013373:Substance P; C032720:substance P (5-11), pGlu(5)-MePhe(8)-MeGly(9)-; D015288:Neurokinin A; D011761:Pyrrolidonecarboxylic Acid