Peptidase inhibitors potentiate the effects of neurotensin and neuromedin N on self-stimulation of the medial prefrontal cortex.
The purpose of this study was to examine the possible role of endogenous peptidases in the inhibition of intracranial self-stimulation (ICSS) produced by injections of neurotensin (NT) and neuromedin N (NN) into the medial prefrontal cortex (MPC) of the rat. We studied the effects on ICSS of the MPC of the administration of thiorphan and bestatin, two specific inhibitors of the peptidases that inactivate NT and NN respectively. Microinjections into MPC of thiorphan (10 micrograms) and bestatin (25 micrograms) potentiated in inhibition of ICSS produced by the intracortical administration of NT (10 nmol) and NN (20 nmol) respectively. This potentiation affected both the amplitude and the duration of the inhibition of ICSS produced by the neuropeptides. Our data indicate that endogenous peptidases are involved in the inactivation of NT and NN in the prefrontal cortex.
Fernández
R
R
Department of Physiology, School of Medicine, University of Granada, Spain.
Alba
F
F
Ferrer
J M
JM
D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D009496:Neurotensin / Q000008:administration & dosage / Q000494:pharmacology*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology*; D011480:Protease Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012653:Self Stimulation / Q000187:drug effects*; D015244:Thiorphan / Q000494:pharmacology
D010446:Peptide Fragments; D011480:Protease Inhibitors; C042090:neuromedin N; D009496:Neurotensin; D015244:Thiorphan; D007930:Leucine; C012211:ubenimex