Summative Action of Acetylcholine with Physiological Stimulus on the Generator Potential in the Lateral Eye of the Horseshoe Crab

Receptor units in the eye of the horseshoe crab are more sensitive to lateral inhibition at some levels of excitation than they are at others. As a result, the steady-state inhibition of the response of a given unit is not directly proportional to the response levels of neighboring units. This effect may be represented by the introduction of a nonlinearity in the Hartline-Ratliff system of equations. The nonlinear inhibitory effect appears to increase the operating range of the receptor units.

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Functional autonomy in the lateral eye of the horseshoe crab, Limulus polyphemus

Vision Research ◽

10.1016/0042-6989(67)90083-1 ◽

1967 ◽

Vol 7 (3-4) ◽

pp. 191-196 ◽

Cited By ~ 4

Author(s):

M.E. Behrens ◽

V.J. Wulff

Keyword(s):

Horseshoe Crab ◽

Limulus Polyphemus ◽

Lateral Eye ◽

Functional Autonomy

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Spectral Sensitivity Comparison of Lateral Eye and Ocellus of Horseshoe Crab*

Journal of the Optical Society of America ◽

10.1364/josa.54.001167 ◽

1964 ◽

Vol 54 (9) ◽

pp. 1167 ◽

Cited By ~ 2

Author(s):

Abner B. Lall ◽

Robert M. Chapman

Keyword(s):

Spectral Sensitivity ◽

Horseshoe Crab ◽

Lateral Eye

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Visions of vision: Studies of the horseshoe crab compound eye

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122848 ◽

1992 ◽

Vol 50 (1) ◽

pp. 488-489

Author(s):

Steven C. Chamberlain

Keyword(s):

Horseshoe Crab ◽

Light Adaptation ◽

Compound Eye ◽

Visually Guided ◽

Morphological Process ◽

Morphological Studies ◽

Visual Processes ◽

Lateral Eye ◽

The Brain

The lateral eye of the horseshoe crab, Limulus polyphemus, is an important model system for studies of visual processes such as phototransduction, lateral inhibition, and light adaptation. It has also been the system of choice for pioneering studies of the role of circadian efferent input from the brain to the eye. For example, light and efferent input interact in controlling the daily shedding of photosensitive membrane and photomechanical movements. Most recently, modeling efforts have begun to relate anatomy, physiology and visually guided behavior using parallel computing. My laboratory has pursued collaborative morphological studies of the compound eye for the past 15 years. Some of this research has been correlated structure/function studies; the rest has been studies of basic morphology and morphological process.

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Putative synaptic mechanisms of inhibition in Limulus lateral eye.

The Journal of General Physiology ◽

10.1085/jgp.67.4.417 ◽

1976 ◽

Vol 67 (4) ◽

pp. 417-431 ◽

Cited By ~ 8

Author(s):

A R Adolph

Keyword(s):

Receptor Potential ◽

Cell Receptor ◽

Ion Concentration ◽

Resting Potential ◽

Equilibrium Potential ◽

Extracellular Potassium ◽

Retinular Cell ◽

Generator Potential ◽

Iontophoretic Application ◽

Lateral Eye

Serotonin (5-HT) perfusion of a thin section of Limulus lateral eye hyperpolarizes retinular and eccentric cell membrane potential, and blocks spike action potentials fired by the eccenteric cell. The indoleamine does not directly affect retinular cell receptor potential or eccenteric cell generator potential in response to light stimuli. LSD perfusion blocks both this inhibitory action of 5-HT and light-evoked, synaptically mediated, lateral inhibition. Iontophoretic application of 5-HT to the synaptic neuropil produces shorter latency and duration and larger amplitude of inhibition than does the perfusion technique. This inhibition is dose dependent; the accompanying inhibitory postsynaptic potential (IPSP) appears to have an equilibrium potential more hyperpolarized than normal resting potential levels of ca. -50 mV. IPSP amplitude is sensitive to extracellular potassium ion concentration: it increases with decreased [K+]0 and decreases with increased [K+]0. LSD blocks the inhibition produced by iontophoretic application of 5-HT. Interaction between light-evoked, natural synaptic transmitter-mediated IPSP's and 5-HT IPSP's suggests a common postsynaptic receptor or transmitter-receptor-permeability change mechanism.

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