title: Cellular distribution of a high-affinity glutamate transporter in the nervous system of the cabbage looper Trichoplusia ni.
abstract: Glutamate functions as a neurotransmitter in the central nervous system (CNS) and neuromuscular junctions in insects. High-affinity glutamate transporters are responsible for keeping the resting levels of excitatory amino acids below the synaptic activation threshold by removing them from the extracellular fluid, thereby preventing them from reaching toxic levels. Peptides representing the N- and C-terminal regions of a glutamate transporter cloned from the cabbage looper caterpillar (Trichoplusia ni) were synthesized and used to generate polyclonal antibodies. The antibodies produced immunohistochemical staining in both muscular and nervous system T. ni tissues. Neuromuscular junctions in the skeletal muscles produced the most intense labelling, but no visceral muscle or sensory nerves were labelled. In the CNS, the neuropile of the ganglia, but not the connectives, gave a diffuse staining. Electron microscopical examination of ganglia and neuromuscular junctions showed that the plasma membrane of glial cells, but not that of neurons was labelled, in agreement with the notion that most of the glutamate uptake sites in this insect are in glial cells.
authors.affiliation: Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Gardiner
authors.forename: Kyrre
authors.initials: K
authors.lastname: Ullensvang
authors.forename: Niels C
authors.initials: NC
authors.lastname: Danbolt
authors.forename: Stanley
authors.initials: S
authors.lastname: Caveney
authors.forename: B Cameron
authors.initials: BC
authors.lastname: Donly
mesh_terms: D027322:Amino Acid Transport System X-AG / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D000918:Antibody Specificity; D007150:Immunohistochemistry; D019476:Insect Proteins / Q000276:immunology / Q000378:metabolism*; D016253:Microscopy, Immunoelectron; D009036:Moths / Q000378:metabolism* / Q000648:ultrastructure; D009420:Nervous System / Q000378:metabolism; D009469:Neuromuscular Junction / Q000378:metabolism
chemical_list: D027322:Amino Acid Transport System X-AG; D019476:Insect Proteins