Glycinergic feedback enhances synaptic gain in the distal retina
Purpura, Lauren A.
MetadataShow full item record
Glycine input originates with interplexiform cells, a group of neurons situated within the inner retina that transmit signals centrifugally to the distal retina. The effect on visual function of this novel mechanism is largely unknown. Using gramicidin-perforated patch whole-cell recordings, intracellular recordings, and specific antibody labeling techniques, we examined the effects of the synaptic connections between glycinergic interplexiform cells, photoreceptors, and bipolar cells. To confirm that interplexiform cells make centrifugal feedback on bipolar cell dendrites, we recorded the post-synaptic glycine currents from axon-detached bipolar cells while stimulating pre-synaptic interplexiform cells. The results show that glycinergic interplexiform cells activate bipolar cell dendrites that express the α3 subunit of the glycine receptor, as well as a subclass of unidentified receptors on photoreceptors. By virtue of their synaptic contacts, glycine centrifugal feedback increases glutamate release from photoreceptors, and suppresses the uptake of glutamate by the EAAT2 transporter on photoreceptors. The net effect is a significant increase in the synaptic gain between photoreceptors and their second-order neurons.
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of the Physiological Society for personal use, not for redistribution. The definitive version was published in Journal of Physiology 592 (2014): 1479-1492, doi:10.1113/jphysiol.2013.265785.
Showing items related by title, author, creator and subject.
Acute increase of α-synuclein inhibits synaptic vesicle recycling evoked during intense stimulation Busch, David J.; Oliphint, Paul A.; Walsh, Rylie B.; Banks, Susan M. L.; Woods, Wendy S.; George, Julia M.; Morgan, Jennifer R. (American Society for Cell Biology, 2014-10-01)Parkinson's disease is associated with multiplication of the α-synuclein gene and abnormal accumulation of the protein. In animal models, α-synuclein overexpression broadly impairs synaptic vesicle trafficking. However, ...
Site-directed mutagenesis studies of Tn5 transposase residues involved in synaptic complex formation Vaezeslami, Soheila; Sterling, Rachel; Reznikoff, William S. (American Society for Microbiology, 2007-08-10)Transposition (the movement of discrete segments of DNA, resulting in rearrangement of genomic DNA) initiates when transposase forms a dimeric DNA-protein synaptic complex with transposon DNA end sequences. The synaptic ...
Gradman, Richard J.; Reznikoff, William S. (American Society for Microbiology, 2007-12-14)A series of Tn5 transposases (Tnp's) with mutations at the conserved amino acid position W450, which was structurally predicted to be important for synapsis, have been generated and characterized. This study demonstrates ...