| Abstract: | The chronic experiments on freely moving cats have shown that the opiate peptides, FK33--824 (Tyr--D--Ala--Gly--MePhe--Met(o)--ol) and tetrapeptide (Tyr--D--Ala--Gly--Phe--NH2), as well as the narcotic analgesics, morphine, phentanyl and pentazocine in doses close to analgesic ones, suppress the recovery cycles of primary responses (PR) in the second somatosensory and associative zones of the brain cortex, recorded at paired stimulation of the fibres of thalamo-cortical radiation (TCR). In larger doses these agents slightly increase PR recorded at single stimulation of TCR, provoke the convulsive discharges on EEG and motor excitation of the animals. Naloxon eliminates all the mentioned effects of the tested opiate peptides and narcotic analgesics. |
