Spectral sensitivity of the goldfish Torus longitudinalis

• Published in: Visual neuroscience 1998-09, Vol.15 (5), p.859-865
• Main Authors: GIBBS, M.A., NORTHMORE, D.P.M.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Carassius auratus; Evoked Potentials, Visual - physiology; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Goldfish - physiology; Logistic Models; Mesencephalon - cytology; Mesencephalon - physiology; Neurons - physiology; Parallel processing; Photic Stimulation; Superior Colliculi - cytology; Superior Colliculi - physiology; Torus longitudinalis; Vertebrates: nervous system and sense organs; Visual behavior
• ISSN: 0952-5238; 1469-8714
• DOI: 10.1017/S0952523898155086

We measured the photopic spectral sensitivity of multiunit activity in the torus longitudinalis and optic tectum of goldfish. Since negative contrast stimuli are most effective for exciting torus longitudinalis, spiking activity was evoked by the shadow of a disc moving through a monochromatic light beam projected upon a screen. The amount of activity evoked in torus longitudinalis generally increased with the monochromatic stimulus radiance at the same rate for all wavelengths, indicating a univariant response. Spiking activity in tectum, however, increased at different rates across the spectrum, indicating color-dependent responses. The action spectra for torus longitudinalis were all similar and relatively flat as expected of a homogeneous, broad-band luminance processing system, and about 1 log unit more sensitive than the tectal action spectra. The latter generally displayed sharp peaks and dips in sensitivity indicative of opponent processing.