Behavioural effects in rats of unilateral and bilateral injections of opiate receptor agonists into the globus pallidus.
Unilateral injections of a putative kappa-opiate receptor agonist, ethylketocyclazocine, into the globus pallidus of rats caused dose-dependent ipsiversive circling which was inhibited by prior systemic administration of the opiate receptor antagonist naloxone. Neither a putative delta-opiate receptor agonist ( [D-Ala2, D-Leu5]enkephalin) nor a putative mu-opiate receptor agonist (Tyr-D-Ala-Gly-MePhe-Met(0)-ol) induced circling behaviour after unilateral intrapallidal injection. Bilateral intrapallidal injection of the delta-opiate receptor agonist or the mu-opiate receptor agonist caused an increase in locomotor activity which in both cases was reduced by systemic administration of naloxone. A specific delta-receptor antagonist, (N,N-bisalyl-Tyr-Gly-Gly-psi-(CH2S)-Phe-Leu-OH) had no effect on the increase in locomotor activity caused by the delta-opiate receptor agonist. Bilateral intrapallidal injection of the kappa-opiate receptor agonist had no effect on locomotor activity. It is suggested that different opiate receptor subtypes within the globus pallidus differentially mediate circling and locomotor behaviour.
Dewar
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Jenner
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Marsden
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D000818:Animals; D003496:Cyclazocine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin / Q000494:pharmacology*; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D016308:Enkephalin, Leucine-2-Alanine; D016314:Ethylketocyclazocine; D005260:Female; D005917:Globus Pallidus / Q000187:drug effects* / Q000502:physiology; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000502:physiology*; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu
D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D016314:Ethylketocyclazocine; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin; D003496:Cyclazocine