A surprising property of electrical spread in the network of rods in the turtle's retina

  title={A surprising property of electrical spread in the network of rods in the turtle's retina},
  author={Peter B Detwiler and Alan Lloyd Hodgkin and Peter A. McNaughton},
Flashing a localised stimulus onto a turtle's retina produces an intracellular potential wave which spreads through electrical connections from illuminated to unilluminated photoreceptors. The response in unilluminated rods (but not in cones) becomes faster as the distance from the source increases, perhaps because voltage-dependent permeability changes in the rod membrane make the coupled network behave like a high-pass filter. 

Behaviour of the rod network in the tiger salamander retina mediated by membrane properties of individual rods

1. The spread of electrical signals between rods in the salamander retina was examined by passing current into one rod and recording the voltage responses in nearby rods. Rod network behaviour,

Differences in the kinetics of rod and cone synaptic transmission

It is found that the kinetics of signal transfer at these chemical synapses parallels the speed of the light-evoked signals themselves.

Ionic basis of high-pass filtering of small signals by the network of retinal rods in the toad

  • V. TorreW. G. Owen
  • Biology
    Proceedings of the Royal Society of London. Series B. Biological Sciences
  • 1981
The electrical spread of excitation in the network of rods was studied by intracellular recording in the isolated perfused retina of the toad Bufo marinus and it was concluded that at least two time-varying voltage-dependent conductances shape the rod photoresponse.

Temporal and spatial characteristics of the voltage response of rods in the retina of the snapping turtle

1. In response to strong, large‐field flashes the dark‐adapted rods of Chelydra serpentina gave initial hyperpolarizing responses of 30‐40 mV, declining rapidly to plateaus of 10‐15 mV which lasted

Current—voltage relations in the rod photoreceptor network of the turtle retina

1. Electrical coupling between rod photoreceptors was studied in the eyecup preparation of the snapping turtle, Chelydra serpentina, using intracellular micro‐electrodes.

Photoreceptor coupling and boundary detection

Bandpass Filtering at the Rod to Second-Order Cell Synapse in Salamander (Ambystoma tigrinum) Retina

It is found that the rod to second-order cell synapse acts as a bandpass filter, preferentially transmitting signals with frequencies between 1.5 and 4 Hz while attenuating higher and lower frequency inputs.

Electrical coupling of photoreceptors in retinal network models

While electrical coupling of photoreceptors in the retina reduces the intrinsic noise in the system, it also improves the sampling efficiency of the laterally coupled neural network of the retina.



Coupling between rod photoreceptors in a vertebrate retina

This work has estimated an individual rod to interact summatively with as many as 200 other rods in the snapping turtle, Chelydra serpentina, and indicates that spatial integration of rod signals occurs at cellular sites proximal to the photoreceptors.

Quantum sensitivity of rods in the toad retina.

A dark-adapted toad rod can respond consistently to flashes of light which bleach an average of less than one pigment molecule in its outer segment. These responses are much less variable in

Kinetics of synaptic transfer from receptors to ganglion cells in turtle retina

1. Synaptic transfer between the retinal input and output was studied in turtle eyecups by injecting rectangular current pulses into a single cone or rod while recording externally from a ganglion

Detection and resolution of visual stimuli by turtle photoreceptors

1. Hyperpolarizing responses up to 30 mV in amplitude were recorded from cones and from certain cells believed to be rods in the isolated retina of the swamp turtle, Pseudemys scripta elegans.

The relation between intercellular coupling and electrical noise in turtle photoreceptors.

1. Intracellular recordings from cones and rods in the retina of the turtle, Pseudemys scripta elegans, revealed that in darkness the cell voltage fluctuated spontaneously about its mean level. The

Light-induced fluctuations in membrane current of single toad rod outer segments

A method for recording the membrane current of a single rod outer segment of photoreceptors based on that used by Neher and Sakmann8 on muscle fibres to try to record elementary events of hyperpolarisation of cells.

Electrical properties of the rod syncytium in the retina of the turtle.

Intracellular responses were recorded from rods in isolated eye‐cups of the snapping turtle and the voltage produced by a large diameter spot became for a short period during the recovery phase less than the voltageproduced by a small diameter spot.

A quantitative description of membrane current and its application to conduction and excitation in nerve.

This article concludes a series of papers concerned with the flow of electric current through the surface membrane of a giant nerve fibre by putting them into mathematical form and showing that they will account for conduction and excitation in quantitative terms.


Longitudinal alternating current impedance measurements have been made on the squid giant axon over the frequency range from 30 cycles per second to 200 kc, indicating that the inductance is in the membrane.