Cultured astrocytes express a spectrum of neurotransmitter receptors. However, little is known about these receptors in situ. We previously reported the absence of (32 adrenergic receptors on astrocytes in multiple sclerosis (MS). Here we used [H-3] - radioligands and receptor autoradiography to screen for a variety of other aminergic receptors in six silent chronic astrogliotic plaques in brain tissue obtained from five patients with MS. Dopamine D, and histamine H, receptors were absent. We detected specific binding for cholinergic muscarinic receptors > dopamine D-2, alpha(1-) and alpha(2) - adrenergic receptors > 5-HT1A, 5-HT1B/D, 5-HT2A, 5-HT2c, 5-HT4, and dopamine D-3 receptors. Radiotracers for these aminergic receptors might b...