Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Spectral Sensitivity of Single Neural Units in the Bullfrog Retinal

Not Accessible

Your library or personal account may give you access

Abstract

Nerve impulses from retinal units, presumably ganglion cells, were elicited by calibrated light flashes of various luminances, wavelengths, and durations, delivered to the eye of the intact bullfrog under scotopic and photopic conditions. Although several response measures were utilized, latency to the first impulse was particularly useful. A simple linear function relating reciprocal of latency to log light luminance was associated with the dark-adapted state and more complex latency-luminance functions were associated with the light-adapted state. Spectral sensitivity curves were derived from these latency-luminance functions by determining the relative energy at the various wavelengths required to produce a criterion latency. A wide variety of relative spectral-sensitivity curves were found. The average shift of spectral sensitivity toward the longer wavelengths (Purkinje shift) between scotopic and photopic conditions was in approximate quantitative agreement with a shift from the rhodopsin to the iodopsin absorption spectrum. The Purkinje shift was also seen in the results obtained from some individual neural units. Among the variety of spectral sensitivity curves obtained from the 20 dark-adapted units, a homogeneous group of curves (11 units) was identified which was well fitted by the rhodopsin absorption curve. Of the 16 light-adapted units, one group (7 units) was roughly fitted by the iodopsin curve. Of special interest to color theory are the units not included in the rhodopsin or iodopsin groups. While none of the curves were completely fitted by Granit’s modulators, many of the sensitivity peaks were at wavelengths that correspond to his green and red modulators (frog). Relatively narrow spectral-sensitivity curves with maxima below 450 mμ were obtained from several of the dark-adapted units; these were reliably different from Granit’s blue modulator (frog) and were approximately fitted by Dartnall’s blue-sensitive pigment.

© 1961 Optical Society of America

Full Article  |  PDF Article
More Like This
Spectral Sensitivity in the Pigeon

Donald S. Blough
J. Opt. Soc. Am. 47(9) 827-833 (1957)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (12)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved