Bipolar cells use kainate and AMPA receptors to filter visual information into separate channels.
Unlike cone photoreceptors, whose light responses have a uniform time course, retinal ganglion cells are tuned to respond to different temporal components in a changing visual scene. The signals in a mammalian cone flow to three to five morphologically distinct "OFF" bipolar cells at a sign-conserving, glutamatergic synapse. By recording simultaneously from pairs of synaptically connected cones and OFF bipolar cells, I now show that each morphological type of OFF bipolar cell receives its signal through a different AMPA or kainate receptor. The characteristic rate at which each receptor recovers from desensitization divides the cone signal into temporal components. Temporal processing begins at the first synapse in the visual system.
DeVries
S H
SH
Department of Ophthalmology and Visual Science, Houston Health Science Center, University of Texas, Houston, TX 77030, USA.
D000818:Animals; D004558:Electric Stimulation; D005456:Fluorescent Dyes; D066298:In Vitro Techniques; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D018091:Receptors, AMPA / Q000378:metabolism*; D018092:Kainic Acid Receptors / Q000378:metabolism*; D012160:Retina / Q000166:cytology / Q000378:metabolism*; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000378:metabolism; D012589:Sciuridae; D013569:Synapses / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology*; D014795:Visual Pathways / Q000166:cytology*
D005456:Fluorescent Dyes; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors