scholarly journals Colour dependence of the early receptor potential and late receptor potential in scallop distal photoreceptor

1983 ◽  
Vol 340 (1) ◽  
pp. 307-334 ◽  
Author(s):  
M. C. Cornwall ◽  
A. L. F. Gorman
Keyword(s):  
Receptor Potential ◽  
Early Receptor Potential ◽  
Late Receptor Potential

scholarly journals Rapid Dark Recovery of the Invertebrate Early Receptor Potential

1973 ◽  
Vol 62 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Peter Hillman ◽  
F. A. Dodge ◽  
S. Hochstein ◽  
B. W. Knight ◽  
B. Minke
Keyword(s):  
Intracellular Recording ◽  
Dark Adaptation ◽  
Receptor Potential ◽  
Visual Pigments ◽  
The State ◽  
Total Recovery ◽  
Time Constants ◽  
Early Receptor Potential ◽  
Late Receptor Potential

The recovery in the dark of the early receptor potential, as a direct manifestation of the state of the visual pigments, has been studied by intracellular recording in the ventral photoreceptors of Limulus and lateral photoreceptors of Balanus. The recovery is exponential with 1/e time constants of about 80 ms at 24°C for both preparations and 1800 ms at 4°C for Balanus. The 24°C rate extrapolates to total recovery of the pigment within 2 s. The later part of the dark adaptation of the late receptor potential, which may take from seconds to minutes in these preparations, appears thus to be unrelated to the state of the pigment.

Responses of Barnacle Photoreceptors to High Energy Flashes of Short Duration

1978 ◽  
Vol 33 (7-8) ◽  
pp. 600-604
Author(s):  
Christof C. Krischer ◽  
R. D. Dahl ◽  
M. Körfer
Keyword(s):  
Kinetic Model ◽  
Short Duration ◽  
Receptor Potential ◽  
High Energy ◽  
Ringer Solution ◽  
Time Span ◽  
Stable States ◽  
Early Receptor Potential ◽  
Late Receptor Potential ◽  
Light Flashes

Abstract In chromatic adapted barnacle median and lateral photo­receptors the two stable states of the photopigment (rhodopsin R and metarhodopsin M) were interconverted with intense, colored light flashes of 1 ms duration. Only after conversion of the red adapted photoreceptor in K+-Ringer solution with an intense flash the negative early receptor potential, ERP (of R) gradually appeared detected with an indicator flash. For the opposite conversion (blue adapted, R→M) the gradual appearence of the positive ERP (M) was not measurable in the same time span. In artificial seawater all flash stimuli yielded - irrespective of color - the transient component of the late receptor potential (LRP). ERP results for the lateral photoreceptor are dis­cussed in view of an existing kinetic model and an attempt is made to give an explanation which covers the new LRP transient and ERP results for both types of photoreceptor (appendix).

scholarly journals Antagonistic Components of the Late Receptor Potential in the Barnacle Photoreceptor Arising from Different Stages of the Pigment Process

1973 ◽  
Vol 62 (1) ◽  
pp. 105-128 ◽  
Author(s):  
S. Hochstein ◽  
B. Minke ◽  
P. Hillman
Keyword(s):  
Strong Dependence ◽  
Red Light ◽  
Receptor Potential ◽  
Photoreceptor Cells ◽  
The Other ◽  
Light Levels ◽  
Early Receptor Potential ◽  
Late Receptor Potential ◽  
A Cell ◽  
532 Nm

The late receptor potential (LRP) recorded in barnacle photoreceptor cells exhibits, at high light levels, a strong dependence on the color of the stimulus and of the preceding adaptation. Most strikingly, red illumination of a cell previously adapted to blue light results in a depolarization which may last for up to 30 min after the light goes off, while blue illumination of a cell previously adapted to red light cuts short this extended depolarization or prevents its induction by a closely following red light. Comparison of the action spectra for the stimulus-coincident LRP and for the extended depolarization and its curtailment with those previously measured for the early receptor potential (ERP) confirms that these phenomena derive from the same bi-stable pigment as the ERP. The stimulus-coincident response and the extended depolarization appear to arise from substantial activation of the stable 532 nm state of the pigment, while activation of the stable 495 state depresses or prevents the extended depolarization and probably also depresses the stimulus-coincident response. Since either process can precede the other, with mutually antagonistic effects, one is not simply the reversal of the other; they must be based on separate mechanisms. Furthermore, comparison with ERP kinetics shows that both processes involve mechanisms additional to the pigment changes, as seen in the ERP. A model is proposed and discussed for the LRP phenomena and their dependences on wavelength, intensity, and duration of illumination based on excitor-inhibitor interactions.

scholarly journals Lability of the prolonged depolarizing afterpotential in Balanus photoreceptors.

1977 ◽  
Vol 70 (4) ◽  
pp. 441-452 ◽  
Author(s):  
R C Lantz ◽  
F Wong ◽  
A Mauro
Keyword(s):  
Decay Time ◽  
Receptor Potential ◽  
Large Cell ◽  
Long Duration ◽  
Early Receptor Potential ◽  
Late Receptor Potential ◽  
Tightly Coupled ◽  
Normal Light ◽  
The Stability ◽  
Prolonged Depolarizing Afterpotential

A large cell to cell variability of the prolonged depolarizing afterpotential (PDA) decay time constant (tau) has been measured in Balanus eberneus lateral ocelli. While 25% of the cells had PDA's of long duration, tau greater than 10 min. 45% of the cells tested showed either weak (tau less than 60 s) PDA or none at all. The variability was not reflected in the late receptor potential. All the cells showed normal light-coincident responses. The variability was not due to some alteration of the thermal stability of the pigment states, since after monochromatic adaptation the amplitude of the early receptor potential remained unchanged for at least 30 min. In addition, in some cells that initially showed PDAs of long duration, the decay time was either shortened or abolished after exposure to anoxia. Again, the late receptor potential and the stability of the pigments remained unaffected. These results indicate that the mechanisms which give rise to the PDA are not always tightly coupled to the direct chain of events that lead to the light-coincident response.

scholarly journals Heterogenic components of a fast electrical potential in Drosophila compound eye and their relation to visual pigment photoconversion.

1980 ◽  
Vol 75 (4) ◽  
pp. 353-379 ◽  
Author(s):  
R S Stephenson ◽  
W L Pak
Keyword(s):  
Visual Pigment ◽  
Compound Eye ◽  
Electrical Potential ◽  
Receptor Potential ◽  
Positive Component ◽  
Flash Intensity ◽  
Pigment System ◽  
Early Receptor Potential ◽  
Late Receptor Potential ◽  
Visual Mutants

The electroretinogram of the dipteran compound eye in response to an intense flash contains an early, diphasic potential that has been termed the M potential. Both phases of the M potential arise from the photostimulation of metarhodopsin. The early, corneal-negative component, the M1, can be recorded intracellularly in the photoreceptors and has properties similar to the classical early receptor potential (ERP). The M1 is resistant to cold, anaesthesia, and anoxia and has no detectable latency. It depends on flash intensity and metarhodopsin fraction in the manner predicted for a closed, two-state pigment system, and its saturation is shown to correspond to the establishment of a photoequilibrium in the visual pigment. On the other hand, the dominant, corneal-positive component, the M2, does not behave like an ERP. It arises, not in the photoreceptors, but deeper in the retina at the level of the lamina, and resembles the on-transient of the electroretinogram in its reversal depth and sensitivity to cooling or CO2. The on-transient, which is present over a much wider range of stimulus intensity than the M potential, has been shown to arise from neurons in the lamina ganglionaris. Visual mutants in which the on-transient is absent or late are also defective in the M2. It is proposed that the M2 and the on-transient arise from the same or similar groups of second-order neurons, and that the M2 is a fast laminar response to the depolarizing M1 in the photoreceptors, just as the on-transient is a fast laminar response to the depolarizing late receptor potential. Unlike the M1, the M2 is not generally proportional to the amount of metarhodopsin photoconverted, and the M2 amplitude is influenced by factors, such as a steady depolarization of the photoreceptor, which do not affect the M1.

scholarly journals Analysis of the rhodopsin cycle in limulus ventral photoreceptors using the early receptor potential.

1976 ◽  
Vol 68 (5) ◽  
pp. 487-501 ◽  
Author(s):  
J E Lisman ◽  
Y Sheline
Keyword(s):  
Red Light ◽  
Receptor Potential ◽  
Maximum Sensitivity ◽  
Chromatic Adaptation ◽  
Early Receptor Potential ◽  
Late Receptor Potential ◽  
In Cells

The early receptor potential (ERP) was recorded intracellularly from Limulus ventral photoreceptors. The ERP in cells dissected under red light was altered by exhaustive illumination. No recovery to the original wafeform was observed, even after 1 h in the dark. The ERP waveform could be further altered by chromatic adaptation or by changes in pH. The results indicate that at pH 7.8 there are two interconvertible pigment states with only slightly different lambdamax, whereas at pH 9.6 there are two interconvertible states with very different lambdamax. Under all conditions studied the ERPs were almost identical with those previously obtained in squid retinas. This strongly suggests that light converts Limulus rhodopsin to a stable photoequilibrium mixture of rhodopsin to a stable photoequilibrium mixture of rhodopsin and metarhodopsin and that, as in squid, the lambdamax of metarhodopsin depends on pH. This conversion at pH 7.8 is associated with a small (0.7 log unit) decrease in the maximum sensitivity of the late receptor potential. Thus the component of adaptation linked to changes in rhodopsin concentration is unimportant in comparison to the "neural" component.

scholarly journals Electrophysiological measurement of the number of rhodopsin molecules in single Limulus photoreceptors.

1977 ◽  
Vol 70 (5) ◽  
pp. 621-633 ◽  
Author(s):  
J E Lisman ◽  
H Bering
Keyword(s):  
Relative Intensity ◽  
Surface Density ◽  
Receptor Potential ◽  
Absolute Intensity ◽  
Charge Movement ◽  
Half Time ◽  
Quantal Response ◽  
Early Receptor Potential ◽  
Electrophysiological Measurement ◽  
Electrophysiological Methods

Two partly independent electrophysiological methods are described for measuring the number of rhodopsin molecules (R) in single ventral photoreceptors. Method 1 is based on measurements of the relative intensity required to elicit a quantal response and the relative intensity required to half-saturate the early receptor potential (ERP). Method 2 is based on measurements of the absolute intensity required to elicit a quantal response. Both methods give values of R approximately equal to 10(9). From these and other measurements, estimates are derived for the surface density of rhodopsin (8,000/micrometer2), the charge movement during the ERP per isomerized rhodopsin (20 X 10(-21) C), and the half-time for thermal isomerization of rhodopsin (36yr).

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