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Localization of a GABA transporter to glial cells in the developing and adult olfactory pathway of the moth Manduca sexta
Author(s) -
Oland Lynne A.,
Gibson Nicholas J.,
Tolbert Leslie P.
Publication year - 2010
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.22244
Subject(s) - neuropil , biology , gaba transporter , manduca sexta , neuroscience , olfactory system , microbiology and biotechnology , transporter , immunocytochemistry , olfactory ensheathing glia , axon , gamma aminobutyric acid , olfactory receptor , olfactory bulb , gabaergic , central nervous system , endocrinology , receptor , biochemistry , inhibitory postsynaptic potential , insect , ecology , gene
Glial cells have several critical roles in the developing and adult olfactory (antennal) lobe of the moth Manduca sexta . Early in development, glial cells occupy discrete regions of the developing olfactory pathway and processes of γ‐aminobutyric acid (GABA)ergic neurons extend into some of these regions. Because GABA is known to have developmental effects in a variety of systems, we explored the possibility that the glial cells express a GABA transporter that could regulate GABA levels to which olfactory neurons and glial cells are exposed. By using an antibody raised against a characterized high‐affinity M. sexta GABA transporter with high sequence homology to known mammalian GABA transporters (Mbungu et al. [1995] Arch. Biochem. Biophys. 318:489–497; Umesh and Gill [2002] J. Comp. Neurol. 448:388–398), we found that the GABA transporter is localized to subsets of centrally derived glial cells during metamorphic adult development. The transporter persists into adulthood in a subset of the neuropil‐associated glial cells, but its distribution pattern as determined by light‐and electron‐microscopic‐level immunocytochemistry indicates that it could not serve to regulate GABA concentration in the synaptic cleft. Instead, its role is more likely to regulate extracellular GABA levels within the glomerular neuropil. Expression in the sorting zone glial cells disappears after the period of olfactory receptor axon ingrowth, but may be important during ingrowth if GABA regulates axon growth. Glial cells take up GABA, and that uptake can be blocked by L‐2,4‐diaminobutyric acid (DABA). This is the first molecular evidence that the central glial cell population in this pathway is heterogeneous. J. Comp. Neurol. 518:815–838, 2010. © 2009 Wiley‐Liss, Inc.