title: Localisation of the high-affinity choline transporter-1 in the rat skeletal motor unit.
abstract: The rate-limiting step in neuronal acetylcholine (ACh) synthesis is the uptake of choline via a high-affinity transporter. We have generated antisera against the recently identified transporter CHT1 to investigate its distribution in rat motor neurons and skeletal muscle and have used these antisera in combination with (1) antisera against the vesicular acetylcholine transporter (VAChT) to identify cholinergic synapses and (2) Alexa-488-labelled alpha-bungarotoxin to identify motor endplates. In the motor unit, immunohistochemistry and RT-PCR have demonstrated that CHT1 is restricted to motoneurons and absent from the non-neuronal ACh-synthesizing elements, e.g. skeletal muscle fibres. In addition, CHT1 is also present in parasympathetic neurons of the tongue, as evidenced by immunohistochemistry and RT-PCR. CHT1 immunoreativity is principally found at all segments (perikaryon, dendrites, axon) of the motoneuron but is enriched at neuro-neuronal and neuro-muscular synapses. This preferential localisation matches well with its anticipated pivotal role in synaptic transmitter recycling and synthesis.
authors.affiliation: Institute for Anatomy and Cell Biology, Justus Liebig University, Aulweg 123, 35385 Giessen, Germany. Katrin.S.Lips@anatomie.med.uni-giessen.de
authors.forename: Katrin S
authors.initials: KS
authors.lastname: Lips
authors.forename: Uwe
authors.initials: U
authors.lastname: Pfeil
authors.forename: Rainer V
authors.initials: RV
authors.lastname: Haberberger
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kummer
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005726:Ganglia, Parasympathetic / Q000166:cytology / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D026901:Membrane Transport Proteins; D009046:Motor Neurons / Q000378:metabolism* / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D050480:Plasma Membrane Neurotransmitter Transport Proteins; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism; D027981:Symporters; D013904:Thoracic Vertebrae; D014059:Tongue / Q000166:cytology / Q000378:metabolism; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins
chemical_list: D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D050480:Plasma Membrane Neurotransmitter Transport Proteins; C493461:Slc18a3 protein, rat; D027981:Symporters; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins; C075746:Slc6a8 protein, rat; D000109:Acetylcholine