Beschreibung:
<jats:title>Abstract</jats:title><jats:p>The locus coeruleus (LC) of the rat was lesioned by microinjection of selective neurotoxins into the brainstem. 6‐Hydroxydopamine (6‐OHDA), 3 μg/μl, given unilaterally at two sites 0.6 mm apart on the rostro‐caudal axis of the LC, was used to lesion catecholamine‐containing neuronal elements. Ibotenic acid, 2.5 μg/0.5 μl, administered similarly was used to lesion nerve cell bodies. Two weeks after administration of the neurotoxin, lesion efficacy was determined based on the norepinephrine content of the cerebral cortex ipsi‐ and contralateral to the lesion. 6‐OHDA lesions of the LC caused a 46% reduction in ipsilateral cortical norepinephrine and a 60% reduction in specific <jats:sup>125</jats:sup>I‐[Sar<jats:sup>1</jats:sup>, Ile<jats:sup>8</jats:sup>]‐angiotensin II (<jats:sup>125</jats:sup>I‐SIAII) binding in the LC. Ibotenic acid lesions of the LC caused a 73% reduction in ipsilateral cortical norepinephrine and a 81% reduction in specific <jats:sup>125</jats:sup>I‐SIAII binding in the LC. These results indicate that All receptor binding sites in the LC are localized on noradrenergic nerve cell bodies or their dendritic and axonal ramifications within the LC.</jats:p>