T P Blackburn

2 papers in the library · 10 citations · publishing 1982

Papers

Involvement of a central dopaminergic system in 5-methoxy-N,N-dimethyltryptamine-induced turning behaviour in rats with lesions of the dorsal raphé nuclei.

Psychopharmacology January 1, 1982 T P Blackburn, B Cox, T F Lee 6 citations

In rats with lesions of the dorsal raphé nucleus, the compound 5-MeODMT caused contralateral turning, similar to its effect in rats with substantia nigra lesions. Ipsilateral turning occurred when 5-MeODMT was given to rats with striatal lesions. The turning behavior in dorsal raphé-lesioned rats was reduced by a second lesion in the striatum but not in the nucleus accumbens, implicating the nigrostriatal dopaminergic system. In substantia nigra slices, 5-MeODMT inhibited dopamine release, an effect blocked by methysergide but not tetrodotoxin, suggesting 5-MeODMT reduces dopamine release from nigral dendrites, enhancing nigrostriatal activity and causing contralateral turning.

DOI: 10.1007/BF00428162 Full text

Possible mechanism of 5-methoxy-N,N-dimethyltryptamine-induced turning behaviour in DRN lesioned rats.

Pharmacology, biochemistry, and behavior January 1, 1982 T P Blackburn, B Cox, C G Heapy et al. 4 citations

In rats with a unilateral lesion of the dorsal raphe nucleus (DRN), the compound 5-MeODMT caused turning toward the opposite side. This behavior was blocked by several serotonin antagonists, including methysergide, cyproheptadine, cinanserin, and the peripheral antagonist xylamidine. Among other neurotransmitter antagonists tested, only haloperidol was effective; hyoscine, picrotoxin, naloxone, and strychnine were not. Pretreatment with alpha-methyl-p-tyrosine also reduced the turning. These results suggest involvement of a central dopaminergic system. Additional lesions of the medial forebrain bundle with 6-OHDA changed the turning direction to the same side, supporting this interpretation.

DOI: 10.1016/0091-3057(82)90004-1 Full text