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Responses of single rods in the retina of the turtle
Author(s) -
Schwartz E. A.
Publication year - 1973
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1973.sp010283
Subject(s) - retina , rod , optics , retinal , stimulus (psychology) , biophysics , materials science , light intensity , anatomy , chemistry , biology , physics , medicine , biochemistry , pathology , psychotherapist , psychology , alternative medicine
1. The responses of rods in the retina of the turtle, Chelydra serpentina , have been studied by intracellular recording. 2. The identification of rods as the origin of the recorded responses has been confirmed by marking with Procion Yellow. 3. The response to a small spot of light was a hyperpolarization which increased with increasing light intensity. For dim, small diameter stimuli, the shape of the rod response was similar to that of cones but 2× slower and 2× larger in amplitude. The time integral of the rod response to a dim, small diameter flash is, therefore, approximately 4× greater than the integral of the cone response. 4. The shape of the rod response depended on the pattern of retinal illumination as well as stimulus intensity. Enlarging the area of illumination increased the peak amplitude and delayed repolarization following a light step. The area of retina which influenced the response was approximately 200 μm in radius. 5. It is concluded that for dim light the responses of rods are larger than those of cones because of (i) a greater response to direct illumination and (ii) an enhancement of response by interaction from a large retinal area.