Light-evoked expansion of subretinal space volume in the retina of the frog.
The retina of the frog was superfused with a Ringer solution containing impermeant "probe" cations and anions. Light-evoked concentration changes in these probe ions were measured in the subretinal space (SRS) with ion-selective microelectrodes. A decrease in probe ion concentration was found, and several observations suggest that this is caused by a light-evoked expansion of the SRS. The probe ion decrease was not seen in the isolated retina; thus, the pigment epithelial (PE) cells are important for its generation. Pharmacological studies suggest that K+ channels in the PE cells are important--perhaps the PE cells shrink in response to the light-evoked decrease in SRS [K+]. The light-evoked decrease of SRS volume may be important in the understanding of SRS solute concentrations, retina-PE adhesivity, photoreceptor-PE cell interactions, and the interphotoreceptor matrix.
Huang
B
B
Department of Psychology, University of Georgia, Athens 30602.
Karwoski
C J
CJ
D000818:Animals; D004596:Electroretinography; D005110:Extracellular Space / Q000378:metabolism; D066298:In Vitro Techniques; D008027:Light; D009407:Nerve Block; D000644:Quaternary Ammonium Compounds; D011894:Rana pipiens; D012160:Retina / Q000033:anatomy & histology / Q000378:metabolism / Q000528:radiation effects*; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology; D013997:Time Factors
D000644:Quaternary Ammonium Compounds; C027917:tetramethylammonium