Differential labelling of afferents to thalamic centromedian-parafascicular nuclei with [3H]choline and D-[3H]aspartate: further evidence for transmitter specific retrograde labelling.
Microinjections of [3H]choline into the rat centromedian-parafascicular nuclei resulted in retrograde labelling of medium sized neurons in brainstem areas considered to comprise the origin of cholinergic innervation; the ipsilateral pedunculopontine tegmental, laterodorsal tegmental and parabrachial nuclei, and, bilaterally, in bulbar reticular formation. In contrast, D-[3H]aspartate labelled the origin of the corticothalamic input, which is believed to use glutamate and/or aspartate as transmitter. In addition, D-[3H]aspartate labelled smaller cells in mesencephalic and pontine periventricular gray, and parabrachial nuclei. It was concluded that retrograde labelling with [3H]choline and D-[3H]aspartate are selective phenomena with specificity for cholinergic and acidic amino acid connections, although occasional labelling of substantia nigra neurons with [3H]choline indicated that unspecific labelling may occur.
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism*; D001345:Autoradiography; D001370:Axonal Transport; D001921:Brain / Q000502:physiology*; D002794:Choline / Q000378:metabolism*; D005260:Female; D051381:Rats; D011919:Rats, Inbred Strains; D013238:Stereotaxic Techniques; D014316:Tritium
D014316:Tritium; D001224:Aspartic Acid; D002794:Choline