Light-evoked changes in extracellular calcium concentration in frog retina.
Light-evoked changes in extracellular Ca2+ concentration were recorded with Ca2(+)-selective microelectrodes in the retina of the frog eyecup. A Ca-decrease at light onset and offset was found in the inner plexiform layer, and its properties are consistent with it resulting from Ca2+ influx into activated neuronal terminals. In the subretinal space, a Ca-increase at light onset and a Ca-decrease at offset were observed, and these likely arise directly from photoreceptors. A slower ON Ca-decrease was also seen here. Because it survives pharmacological isolation of the photoreceptors from post-synaptic interactions, but not physical isolation of the retina from the pigment epithelium, this component probably depends on pigment epithelial activity.
Livsey
C T
CT
Department of Psychology, University of Georgia, Athens 30602.
Huang
B
B
Xu
J
J
Karwoski
C J
CJ
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism* / Q000528:radiation effects; D066298:In Vitro Techniques; D008027:Light; D008564:Membrane Potentials; D008839:Microelectrodes; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000378:metabolism / Q000528:radiation effects; D011894:Rana pipiens; D012160:Retina / Q000378:metabolism* / Q000528:radiation effects
D002118:Calcium