Immunocytochemical localization of a Manduca sexta gamma-aminobutyric acid transporter.
Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in insect central and peripheral nervous systems. Although much work has focused on the downstream targets of GABA, signal termination at insect GABAergic synapses has received very little attention. One of the major mechanisms of terminating synaptic transmission involves transport of the neurotransmitter molecules into presynaptic neurons or surrounding glia. Here we report the immunolocalization of a GABA transporter in the tobacco hornworm, Manduca sexta (MasGAT), using an affinity-purified antibody developed to the C-terminus. This is the first demonstration of an insect neurotransmitter transporter immunolocalization study. Results showed strong staining in the neuropil regions of embryonic, larval, and pharate adult central nervous system. Expression pattern in the pharate adult brain mostly mimicked that observed for GABA, with staining in parts of the optic and antennal lobes, mushroom body, lateral protocerebrum, and central complex. Certain longitudinal and lateral connectives of ganglia were observed to have immunostained fibers representing axons. These data support the view that GABA is involved in visual and olfactory processing in the insect brain.
Environmental Toxicology Graduate Program, Department of Cell Biology and Neuroscience, University of California-Riverside, Riverside, CA 92521, USA.
Anita
A
Umesh
Sarjeet S
SS
Gill
D000375:Aging / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D002490:Central Nervous System / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D050485:GABA Plasma Membrane Transport Proteins; D007150:Immunohistochemistry; D007814:Larva / Q000378:metabolism; D018402:Manduca / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D027361:Organic Anion Transporters; D014018:Tissue Distribution
D002352:Carrier Proteins; D050485:GABA Plasma Membrane Transport Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027361:Organic Anion Transporters