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Evidence for Ca(2+)-permeable AMPA receptors in the olfactory bulb.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Blakemore, Laura J. Resasco, Massimo Mercado, Miguel Ángel Trombley, Paul Q. |
| Copyright Year | 2006 |
| Abstract | alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (AMPARs), a subtype of glutamate receptor, contribute to olfactory processing in the olfactory bulb (OB). These ion channels consist of various combinations of the subunits GluR1-GluR4, which bestow certain properties. For example, AMPARs that lack GluR2 are highly permeable to Ca(2+) and generate inwardly rectifying currents. Because increased intracellular Ca(2+) could trigger a host of Ca(2+)-dependent odor-encoding processes, we used whole cell recording as well as histological and immunocytochemical (ICC) techniques to investigate whether AMPARs on rat OB neurons flux Ca(2+). Application of 1-naphthylacetyl spermine (NAS), a selective antagonist of Ca(2+)-permeable AMPARs (CP-AMPARs), inhibited AMPAR-mediated currents in subsets of interneurons and principal cells in cultures and slices. The addition of spermine to the electrode yielded inwardly rectifying current-voltage plots in some cells. In OB slices, olfactory nerve stimulation elicited excitatory responses in juxtaglomerular and mitral cells. Bath application of NAS with d,l-2-amino-5-phosphonovaleric acid (AP5) to isolate AMPARs suppressed the amplitudes of these synaptic responses compared with responses obtained using AP5 alone. Co(2+) staining, which involves the kainate-stimulated influx of Co(2+) through CP-AMPARs, produced diverse patterns of labeling in cultures and slices as did ICC techniques used with a GluR2-selective antibody. These results suggest that subsets of OB neurons express CP-AMPARs, including functional CP-AMPARs at synapses. Ca(2+) entry into cells via these receptors could influence odor encoding by modulating K(+) channels, N-methyl-d-aspartate receptors, and Ca(2+)-binding proteins, or it could facilitate synaptic vesicle fusion. |
| Starting Page | 293 |
| Ending Page | 293 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://ajpcell.physiology.org/content/ajpcell/290/3/C925.full.pdf |
| PubMed reference number | 16267106v1 |
| Volume Number | 290 |
| Issue Number | 3 |
| Journal | American journal of physiology. Cell physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | 1-naphthylacetyl spermine AMPA Receptors Aspartic Acid Calcium Cerebral Palsy Glutamate Receptor Glutamic Acid Hippocampus (Brain) Interneurons Ion Channel Iontophoresis Kainate N-Methyl-D-Aspartate Receptors N-Methylaspartate Odors Olfactory Nerve Potassium Propionibacterium acnes Smell Perception Structure of olfactory bulb Synapses Synaptic Vesicles Thioctic Acid Vesicle (morphologic abnormality) synaptic vesicle fusion voltage |
| Content Type | Text |
| Resource Type | Article |
