The neurotensin analog xenopsin excites nigral dopamine neurons.
The electrophysiological effects of neurotensin (NT), its analog xenopsin, and the fragment NT-(1-8) on the activity of dopaminergic neurons in rat substantia nigra slices were compared. Xenopsin and NT produced a concentration-dependent increase in the firing rate. The mean firing rate was increased by 58.5% with xenopsin (0.1 microM) and 49.1% with NT (0.1 microM). NT-(1-8) was inactive at this concentration. Dopamine (100 microM) inhibited firing in these neurons by 54.7%. These data provide evidence that xenopsin mimics the physiological effects of NT.
Pozza
M F
MF
Biology Research Department, Ciba-Geigy Ltd., Basel, Switzerland.
Küng
E
E
Bischoff
S
S
Olpe
H R
HR
D000200:Action Potentials; D000818:Animals; D008297:Male; D009474:Neurons / Q000187:drug effects*; D009496:Neurotensin / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D013378:Substantia Nigra / Q000187:drug effects*; D029867:Xenopus Proteins
D009842:Oligopeptides; D010446:Peptide Fragments; D010455:Peptides; D011954:Receptors, Dopamine; D029867:Xenopus Proteins; D009496:Neurotensin; C016832:xenopsin; C041968:neurotensin (1-8); D011761:Pyrrolidonecarboxylic Acid