Selective retrograde labelling of vestibular efferent neurons with [3H]choline.
Following administration of [3H]choline in the lateral semicircular canal of the cat labyrinth, bidirectional axoplasmic transport [3H]choline and its derivatives was shown by radioautography in the vestibular system. Light-microscopic radioautographs exhibited various patterns of radioautographic labelling. First, a diffuse reaction was observed in vestibular nuclei representing anterograde-labelled, vestibular nerve endings. Second, a heavy labelling limited to perikarya was detected in efferent vestibular neurons and corresponded to retrograde transport. The anterograde migration of [3H]choline is known to be non-selective and is related to synthesis of phospholipids, non-diffusable molecules. In contrast, the retrograde perikaryal labelling seems highly selective and related to the cholinergic specificity of the transmitter. The selectivity of such labelling offers a further possibility of identifying cholinergic neurons and is additional evidence that cholinergic mechanisms are involved in the efferent vestibular control.
D000818:Animals; D001345:Autoradiography; D001931:Brain Mapping; D002415:Cats; D002794:Choline / Q000378:metabolism*; D004292:Dominance, Cerebral / Q000502:physiology; D004525:Efferent Pathways / Q000033:anatomy & histology; D009412:Nerve Fibers / Q000648:ultrastructure; D012665:Semicircular Canals / Q000294:innervation*; D014725:Vestibular Nerve / Q000033:anatomy & histology*; D014726:Vestibular Nuclei / Q000033:anatomy & histology*
D002794:Choline