title: Effect of neonatal axoplasmic transport attenuation in the infraorbital nerve on vibrissae-related patterns in the rat's brainstem, thalamus and cortex.
abstract: This study evaluated the effects of neonatal attenuation of axoplasmic transport in the infraorbital nerve (ION) on the organization of vibrissae-related patterns in the rat's CNS. Application of colchicine- or vinblastine- impregnated implants to the ION from birth until postnatal day (P)6 to P10 resulted in a 92.4% reduction in the number of trigeminal (V) ganglion cells labelled by application of horseradish peroxidase to the vibrissa pad and a 44.8% decrease in the number of Nissl-stained ganglion cells in the ophthalamic-maxillary portion of the V ganglion. These implants also decreased the number of myelinated fibres in the ION. In normal rats killed on P6-10, there was an average of 10273 +/- 1259 myelinated axons in the nerve. In the animals with colchicine- or vinblastine-treated implants, this value was 3891 +/- 1965. The highest axon count in an experimental animal was 9859. In all animals, axoplasmic transport attenuation resulted in the disappearance of normal vibrissae-related cytochrome oxidase patterns in the brainstem, thalamus and primary somatosensory cortex. Axoplasmic transport attenuation did not result in the disappearance of vibrissae-related ordering of V primary afferent terminal arbors, as demonstrated by anterograde labelling with neurobiotin. These results suggest that some factor conveyed from the periphery of the V ganglion and perhaps on to the brainstem is necessary for the maintenance of vibrissae-related patterns in the thalamus and cortex.
authors.affiliation: Department of Anatomy and Neurobiology, Medical College of Ohio, Toledo 43699-0008, USA.
authors.forename: N L
authors.initials: NL
authors.lastname: Chiaia
authors.forename: C A
authors.initials: CA
authors.lastname: Bennett-Clarke
authors.forename: R S
authors.initials: RS
authors.lastname: Crissman
authors.forename: L
authors.initials: L
authors.lastname: Zheng
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.forename: R W
authors.initials: RW
authors.lastname: Rhoades
mesh_terms: D000344:Afferent Pathways / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D001370:Axonal Transport / Q000187:drug effects*; D001933:Brain Stem / Q000187:drug effects* / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D003078:Colchicine / Q000494:pharmacology; D017950:Ganglia, Sensory / Q000187:drug effects; D009411:Nerve Endings / Q000187:drug effects; D009413:Nerve Fibers, Myelinated / Q000187:drug effects; D009915:Orbit / Q000294:innervation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013788:Thalamus / Q000187:drug effects* / Q000378:metabolism; D014738:Vibrissae / Q000502:physiology*; D014747:Vinblastine / Q000494:pharmacology
chemical_list: D014747:Vinblastine; D003078:Colchicine