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Positron emission tomography (PET) studies of dopaminergic/cholinergic interaction in the baboon brain
Author(s) -
Dewry Stephen L.,
Brodie Jonathan D.,
Fowler Joanna S.,
MacGregor Robert R.,
Schlyer David J.,
King Payton T.,
Alexoff David L.,
Volkow Nora D.,
Shiue ChyngY.,
Wolf Alfred P.,
Bendriem Bernard
Publication year - 1990
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.890060403
Subject(s) - benztropine , dopaminergic , striatum , chemistry , cholinergic , medicine , endocrinology , pharmacology , dopamine , neuroscience , psychology
Interactions between the dopaminergic D 2 recceptor system and the muscarinic cholinergic system in the corpus striatum of adult female baboons ( Papio anubis ) were examined using positron emission tomography (PET) combined with [ 18 F] N ‐methylspiroperidol ([ 18 ]NMSP) (to probe D 2 receptor availability) and [N‐ 11 C‐methyl]benztropine (to probe muscarinic cholinergic receptor availability). Pretreatment with benztropine, a long‐lasting anticholinergic drug, bilaterally reduced the incorporation of radioactivity in the corpus striatum but did not alter that observed in the cerebellum or the rate of metabolism of [ 18 F]NMSP in plasma. Pretreatment with unlabelled NMSP, a potent dopaminergic antagonist, reduced the incorporation of [N‐ 11 C‐methyl]benztropine in all brain regions, with the greatest effect being in the corpus striatum < cortex < thalamus < cerebellum, but did not alter the rate of metabolism of the labelled benztropine in the plasma. These reduction in the incorporation of either [ 18 F]NMSP or [N‐ 11 C‐methyl]benztropine exceeded the normal variation in tracer incorporation in repeated studies in the same animal. This study demonstrates that PET can be used as a tool for investigating interactions between neurochemically different yet functionally linked neurotransmitters systems in vivo and provides insight into the consequences of multiple pharmocologic administration.