Quantitative autoradiographic analysis of muscarinic receptor subtypes and their role in representational memory

Thesis/Dissertation · Tue Dec 31 23:00:00 EST 1985

OSTI ID:6478783

Messer, W S

Autoradiographic techniques were used to examine the distribution of muscarinic receptors in rat brain slices. Agonist and selective antagonist binding were examined by measuring the ability for unlabeled ligands to inhibit (/sup 3/H)-1-QNB labeling of muscarinic receptors. The distribution of high affinity pirenzepine binding sites (M/sub 1/ subtype) was distinct from the distribution of high affinity carbamylcholine sites, which corresponded to the M/sub 2/ subtype. In a separate assay, the binding profile for pirenzepine was shown to differ from the profile for scopolamine, a classical muscarinic antagonist. Muscarinic antagonists, when injected into the Hippocampus, impaired performance of a representational memory task. Pirenzepine, the M/sub 1/ selective antagonist, produced representational memory deficits. Scopolamine, a less selective muscarinic antagonist, caused increases in running times in some animals which prevented a definitive interpretation of the nature of the impairment. Pirenzepine displayed a higher affinity for the hippocampus and was more effective in producing a selective impairment of representational memory than scopolamine. The data indicated that cholinergic activity in the hippocampus was necessary for representation memory function.

• Research Organization: Rochester Univ., NY (USA)
• OSTI ID: 6478783
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AUTORADIOGRAPHY
BEHAVIOR
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
DRUGS
KINETICS
LABELLED COMPOUNDS
LEARNING
LIGANDS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SYMPATHOMIMETICS
TRITIUM COMPOUNDS
VERTEBRATES