Quantitative autoradiography of neurotransmitter receptors in Huntington disease

Abstract

GABA benzodiazepine and muscarinic cholinergic receptor-binding were studied by quantitative autoradiography [using flunitrazepam, muscimol, clonazepam and quinuclidinylbenzilate]. In coronal sections from the brain of a patient with Huntington disease, binding for all 3 receptors in caudate and putamen was lower than control values. Binding to GABA and benzodiazepine receptors was increased in lateral and medial pallidum and decreased in ventrolateral thalamus. Muscarinic cholinergic receptors were markedly decreased in pallidum but not thalamus. Loss of striatal afferents to both segments of pallidum may result in GABA and benzodiazepine receptor supersensitivity; the use of quantitative autoradiography for receptor studies in human postmortem material is supported.