Mapping kainate activation of inner neurons in the rat retina. Issue 11 (4th June 2013)

• Record Type: Journal Article
• Authors: Nivison‐Smith, Lisa; Sun, Daniel; Fletcher, Erica L.; Marc, Robert E.; Kalloniatis, Michael
• Is Part Of: Journal of comparative neurology. Volume 521:Issue 11(2013:Aug. 01)
• Page Start: 2416
• Page End: 2438
• Publication Date: 2013-06-04
• Subjects: kainate -- kainate receptors -- agmatine -- AGB -- rat retina -- glutamate -- GABA -- glycine -- immunocytochemistry; Comparative neurobiology -- Periodicals; Neurology -- Periodicals; 616
• DOI: 10.1002/cne.23305
• Languages: English
• ISSNs: 0021-9967

Abstract

Abstract: Kainate receptors mediate fast, excitatory synaptic transmission for a range of inner neurons in the mammalian retina. However, allocation of functional kainate receptors to known cell types and their sensitivity remains unresolved. Using the cation channel probe 1‐amino‐4‐guanidobutane agmatine (AGB), we investigated kainate sensitivity of neurochemically identified cell populations within the structurally intact rat retina. Most inner retinal neuron populations responded to kainate in a concentration‐dependent manner. OFF cone bipolar cells demonstrated the highest sensitivity of all inner neurons to kainate. Immunocytochemical localization of AGB and macromolecular markers confirmed that type 2 bipolar cells were part of this kainate‐sensitive population. The majority of amacrine (ACs) and ganglion cells (GCs) showed kainate responses with different sensitivities between major neurochemical classes (γ‐aminobutyric acid [GABA]/glycine ACs > glycine ACs > GABA ACs; glutamate [Glu]/weakly GABA GCs > Glu GCs). Conventional and displaced cholinergic ACs were highly responsive to kainate, whereas dopaminergic ACs do not appear to express functional kainate receptors. These findings further contribute to our understanding of neuronal networks in complex multicellular tissues. J. Comp. Neurol. 521:2416–2438, 2013. © 2013 Wiley Periodicals, Inc. Abstract : [Graphic abstract text]Using the probe agmatine, we found that kainate sensitivity is highest in OFF bipolar cells (particularly type 2) followed by ganglion cells. GABA/glycine amacrine cells (ACs) are the most sensitive ACs, followed by glycine and GABA ACs. Cholinergic ACs are highly responsive, but dopaminergic ACs do not express functional kainate receptors.