Morphology and ultrastructure of anterior thalamic neurons solidly labeled with horseradish peroxidase.

'Golgi-like' labeling of anterior thalamic neurons was achieved by injecting horseradish peroxidase dissolved in dimethylsulfoxide (DMSO) into the striatum of the rabbit. Forty-eight hours after injection, elements of the presumed thalamocortical population of anterior thalamic neurons are diffused filled with HRP to the extent that their dendritic arborizations, and even spinous processes, can be readily characterized. Ultrastructurally, these solidly labeled thalamic neurons are seen to contain large, irregular electron dense granules dispersed within a moderately electron dense cytoplasm.