Fast axonal transport of the vesicular acetylcholine transporter (VAChT) in cholinergic neurons in the rat sciatic nerve.
The sciatic nerve, as a part of the peripheral nervous system (PNS), has been used to study axonal transport for decades. It contains motor, sensory as well as autonomic axons. The present study has concentrated on the axonal transport of the synaptic vesicle acetylcholine transporter (VAChT), using the "stop-flow/nerve crush" method. After blocking fast axonal transport by means of a crush, distinct accumulations of various synaptic vesicle proteins, including VAChT, and peptides developed during the first hour after crush-operation and marked increases were observed up to 8 h post-operative. Semiquantitative analysis, using cytofluorimetric scanning (CFS) of immuno-incubated sections, revealed a rapid rate of accumulation proximal to the crush, and that the ratio between distal accumulations (organelles in retrograde transport) and proximal accumulations (organelles in anterograde transport) was about 40%. Most synaptic vesicle proteins were colocalized in the axons proximal to the crush. VAChT-immunoreactive axons were also immunoreactive for choline acetyltransferase (ChAT). Autonomic axons with VAChT also contained VIP-LI. The results demonstrate (1) that VAChT, as well as other synaptic vesicle proteins, is transported with fast axonal transport in motor axons as well as in autonomic post-ganglionic neurons in this nerve, (2) VAChT colocalized in motor axons with SV2 as well as with synaptophysin, indicating storage in the same axonal particle, (3) in the autonomic postganglionic sympathetic cholinergic fibres, VAChT colocalized with VIP, but VIP-LI was present in rather large granular structures while VAChT-LI was present mostly as small granular elements, (4) in motor as well as in autonomic axons ChAT-LI was present in VAChT-positive axons, and (5) the ratio of recycling (retrogradely accumulated) VAChT-IR was about 40%, in contrast to the recycling fraction of synaptophysin that was about 70%.
Department of Anatomy and Cell Biology, University of Göteborg, Medicinaregatan, Sweden. jiayi.li@anatcell.gu.se
J Y
JY
Li
A M
AM
Dahlström
L B
LB
Hersh
A
A
Dahlström
D000818:Animals; D001341:Autonomic Nervous System / Q000166:cytology / Q000378:metabolism; D001370:Axonal Transport / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism*; D002799:Cholinergic Fibers / Q000378:metabolism*; D008161:Lumbosacral Region; D008297:Male; D026901:Membrane Transport Proteins; D009046:Motor Neurons / Q000378:metabolism; D009409:Nerve Crush; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000378:metabolism*; D013997:Time Factors; D014018:Tissue Distribution; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; D026901:Membrane Transport Proteins; C493461:Slc18a3 protein, rat; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins