A neuroanatomical study of analgesia and catatonia induced by etorphine in the rat

Academic Article


  • Rats were injected with 1 μg (in 1 μl volume) of etorphine in one of 11 different neuroanatomical sites. The flinch-jump technique was used to measure analgesia and the bar test was used to assess catatonia. Etorphine injections into the periaqueductal gray (PAG), cerebral aqueduct (AQ). midbrain reticular formation (MRF), and medial thalamus (MT), produced both analgesia and catatonia. There was no significant difference in the degree of analgesia produced among these sites; however, the degree of catatonia at the reticular formation site was significantly lower than the catatonia elicited at other "catatonia-positive" sites. Etorphine injections into the cerebellum (CB) and cortico-medial amygdala (CMA) produced catatonia without analgesia. Etorphine injections into the following areas produced neither analgesia nor catatonia: basolateral amygdala (BLA); caudate-putamen (CPU), hippocampus (HP), nucleus accumbens (ACB), and globus pallidus (GP). The results suggest neuroanatomical specificity and some degree of differing sensitivity. © 1981.
  • Authors

    Published In

  • Neuropharmacology  Journal
  • Digital Object Identifier (doi)

    Author List

  • Thorn-Gray BE; Levitt RA; Hill J; Ward K
  • Start Page

  • 763
  • End Page

  • 767
  • Volume

  • 20
  • Issue

  • 8