INITIATION OF EXCITATION AND LIGHT ADAPTATION IN LIMULUS VENTRAL PHOTORECEPTORS

被引:52
作者
LISMAN, JE
STRONG, JA
机构
[1] Department of Biology, Brandeis University, Waltham, MA
[2] Department of Physiology, Yale University School of Medicine, New Haven, CT
关键词
D O I
10.1085/jgp.73.2.219
中图分类号
Q4 [生理学];
学科分类号
071003 ;
摘要
Two types of experiments indicate that light adaptation and excitation are initiated by the same, rather than different, populations of visual pigment, (a) The criterion action spectra of light adaptation and excitation are the same, (b) Increment-threshold curves were measured with a voltage-clamp technique under conditions of high and low concentration of plasma membrane rhodopsin (Rhpm). SD, the dark-adapted sensitivity, and l//2, the inverse of the background irradiance that desensitized by 0.3 log units, underwent the same fractional change when the rhodopsin concentration was changed. Both quantities appear to be linearly related to Rhpm. Reversible reductions in Rhpm were achieved by orange irradiation during a brief increase of extracellular pH from 7.8 to 10. This procedure would be unlikely to produce similar concentration changes in a hypothetical intracellular pigment because the concurrent change in intracellular pH, measured using the dye, phenol red, was only 0.45 pH units. It is thus unlikely that an intracellular pigment initiates light adaptation. On the assumption that light adaptation is mediated by a light-induced release of Ca++ from an intracellular store, the results reported here imply that an intracellular transmitter is needed to couple Rhpm to the intracellular store. © 1979, Rockefeller University Press., All rights reserved.
引用
收藏
页码:219 / 243
页数:25
相关论文
共 46 条
[1]  
BICHER H, 1972, BIOCH BIOPHYS ACTA, V255, P902
[2]   IONIC DEPENDENCE OF REVERSAL VOLTAGE OF LIGHT RESPONSE IN LIMULUS VENTRAL PHOTORECEPTORS [J].
BROWN, JE ;
MOTE, MI .
JOURNAL OF GENERAL PHYSIOLOGY, 1974, 63 (03) :337-350
[3]   INTRACELLULAR CA MODULATES SENSITIVITY AND TIME SCALE IN LIMULUS VENTRAL PHOTORECEPTORS [J].
BROWN, JE ;
LISMAN, JE .
NATURE, 1975, 258 (5532) :252-254
[4]   DETECTION OF LIGHT-INDUCED-CHANGES OF INTRACELLULAR IONIZED CALCIUM CONCENTRATION IN LIMULUS VENTRAL PHOTORECEPTORS USING ARSENAZO III [J].
BROWN, JE ;
BROWN, PK ;
PINTO, LH .
JOURNAL OF PHYSIOLOGY-LONDON, 1977, 267 (02) :299-320
[5]   CHANGES IN INTRACELLULAR FREE CALCIUM CONCENTRATION DURING ILLUMINATION OF INVERTEBRATE PHOTORECEPTORS - DETECTION WITH AEQUORIN [J].
BROWN, JE ;
BLINKS, JR .
JOURNAL OF GENERAL PHYSIOLOGY, 1974, 64 (06) :643-665
[6]  
CONE RA, 1973, BIOCH PHYSL VISUAL P, P275
[7]   VOLTAGE NOISE IN LIMULUS VISUAL CELLS [J].
DODGE, FA ;
KNIGHT, BW ;
TOYODA, J .
SCIENCE, 1968, 160 (3823) :88-&
[8]   SENSITIVITY OF TOAD RODS - DEPENDENCE ON WAVELENGTH AND BACKGROUND ILLUMINATION [J].
FAIN, GL .
JOURNAL OF PHYSIOLOGY-LONDON, 1976, 261 (01) :71-+
[9]   LOCALIZED DESENSITIZATION OF LIMULUS PHOTORECEPTORS PRODUCED BY LIGHT OR INTRACELLULAR CALCIUM-ION INJECTION [J].
FEIN, A ;
LISMAN, J .
SCIENCE, 1975, 187 (4181) :1094-1096
[10]   QUANTITATIVE COMPARISON OF EFFECTS OF INTRACELLULAR CALCIUM INJECTION AND LIGHT ADAPTATION ON PHOTORESPONSE OF LIMULUS VENTRAL PHOTORECEPTORS [J].
FEIN, A ;
CHARLTON, JS .
JOURNAL OF GENERAL PHYSIOLOGY, 1977, 70 (05) :591-600