Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-27T10:56:57.183Z Has data issue: false hasContentIssue false

Contrast Sensitivity Function of the Albino Rat Determined Electrophysiologically

Published online by Cambridge University Press:  10 April 2014

Pilar Herreros de Tejada*
Affiliation:
Complutense University of Madrid
Carmen Muñoz Tedó*
Affiliation:
Complutense University of Madrid
*
*Correspondence concerning this article should be addressed to the authors, Departamento de Psicobiología, Facultad de Psicología. Campus de Somosaguas. 28223-Madrid (Spain). E-mail: pspsc03@sis.ucm.es, cmt@sis.ucm.es
*Correspondence concerning this article should be addressed to the authors, Departamento de Psicobiología, Facultad de Psicología. Campus de Somosaguas. 28223-Madrid (Spain). E-mail: pspsc03@sis.ucm.es, cmt@sis.ucm.es

Abstract

Albinism alters the neural projections of the visual system. The authors wondered how this would affect visual function in rodents. They had previously shown that it doesn't alter the luminance threshold. They now explore visual acuity in the albino rat. In this work, they describe its contrast sensitivity function (CSF), as determined electro-physiologically. They recorded cortical visual evoked potentials (VEP) on six albino rats, stimulated by sinusoidal contrast reversal gratings. The curve showed the same characteristics that this function has in other mammals. Compared with the pigmented rat, the albino reached lower sensitivity values and showed a loss of sensitivity at high spatial frequencies. The estimated cut-off was 0.48 c/°, that is, 0.72 log units below the estimated cut-off for the pigmented rat under similar experimental conditions. VEP and behavioral cut-off were very close, the VEP estimation being slightly higher than the behavioral one.

El albinismo altera las proyecciones neurales del sistema visual. Nos planteamos qué efecto puede tener sobre la función visual en roedores. En trabajos previos hemos mostrado que el albinismo no altera el umbral de luminancia. En el presente trabajo hemos explorado la agudeza visual de la rata albina. Describimos la función de sensibilidad al contraste (FSC) determinada electrofisiológicamente mediante registros de potenciales evocados visuales (PEV) en seis ratas albinas que eran estimuladas por enrejados sinusoidales. La curva presenta las mismas características definitorias que esta función tiene en otros mamíferos. Comparada con la rata pigmentada, la rata albina alcanza unos valores de sensibilidad más bajos y muestra una pérdida de la sensibilidad para las frecuencias espaciales altas. La frecuencia de corte estimada es 0.48 c/°, es decir, 0.72 unidades logarítmicas más baja que la frecuencia de corte estimada para la rata pigmentada en condiciones experimentales similares. Las frecuencias de corte estimadas conductualmente o mediante registros de PEV están muy próximas, siendo la estimación electrofisiológica un poco más alta que la conductual.

Type
Articles
Copyright
Copyright © Cambridge University Press 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Balkema, G.W. (1988). Elevated dark-adapted thresholds in albino rodents. Investigative Ophthalmology and Visual Science, 29, 544549.Google ScholarPubMed
Birch, D., & Jacobs, G.H. (1979). Spatial contrast sensitivity in albino and pigmented rats. Vision Research, 19, 933937.CrossRefGoogle ScholarPubMed
Boyes, W.K., & Dyer, R.S. (1983). Pattern reversal visual evoked potentials in awake rats. Brain Research Bulletin, 10, 817823.CrossRefGoogle ScholarPubMed
Drager, U.C., & Olsen, J.F. (1980). Origins of crossed and uncrossed retinal projections in pigmented and albino mice. Journal of Comparative Neurology, 191, 383412.CrossRefGoogle ScholarPubMed
Dyer, R.S., & Swartzwelder, S.H. (1978). Sex and strain differences in the visual evoked potentials of albino and hooded rats. Pharmacology, Biochemistry and Behavior, 9, 301306.CrossRefGoogle ScholarPubMed
Guillery, R.W. (1974). Visual pathways in albinos. Scientific American, 230, 4454.CrossRefGoogle ScholarPubMed
Harnois, C., Bodis-Wollner, I., & Onofrj, M. (1984). The effect of contrast and spatial frequency on the visual evoked potential of the hooded rat. Experimental Brain Research, 57, 18.CrossRefGoogle ScholarPubMed
Hayes, J.M., & Balkema, G.W. (1993). Elevated dark adapted thresholds in hypopigmented mice measured with a water maze screening apparatus. Behavior Genetics, 23, 395403.CrossRefGoogle ScholarPubMed
Herreros de Tejada, P., Green, D.G., & Glover, M.J. (1994). Electrophysiological estimates of visual sensitivity in albino and pigmented mice. Visual Neuroscience, 11, 919925.Google Scholar
Herreros de Tejada, P., Tedó, Muñoz, & , C., Costi, C. (1997). Behavioral estimates of absolute visual threshold in mice. Vision Research, 37, 24272432.CrossRefGoogle ScholarPubMed
Heywood, C.A., Silveira, L.C.L., & Cowey, A. (1988). Contrast sensitivity in rats with increased or decreased numbers of retinal ganglion cells. Experimental Brain Research, 70, 513526.CrossRefGoogle Scholar
LaVail, M.M., Nixon, R.A., & Sidman, R.L. (1978). Genetic control of retinal ganglion cell projections. Journal of Comparative Neurology, 182, 399422.CrossRefGoogle ScholarPubMed
Legg, C.R. (1984). Contrast sensitivity at low spatial frequencies in the hooded rat. Vision Research, 24, 159161.CrossRefGoogle ScholarPubMed
Lund, R.D. (1965) Uncrossed visual pathways of hooded and albino rats. Science, 149, 15061507.CrossRefGoogle ScholarPubMed
Maffei, L. (1978). Spatial Frequency Channels: Neural Mechanisms. In Held, A.C., Leibowitz, H.W., & Teuber, H. (Eds.), Handbook of sensory physiology (Vol. VIII, pp. 3766). New York: L. Springer Verlag.Google Scholar
Montero, V.M., Rojas, A., & Torrealba, F. (1973). Retinotopic organization of striate and prestriate visual cortex in the albino rat. Brain Research, 53, 197201.CrossRefGoogle Scholar
Muñoz Tedó, C., Herreros de Tejada, P., & Cañavate, A. (1992). Estudios fisiológicos y conductuales de la detección de frecuencias espaciales en roedores. Investigaciones Psicológicas, 11, 8397.Google Scholar
Muñoz Tedó, C., Herreros de Tejada, P., & Green, D.G. (1994). Behavioral estimates of absolute thresholds in rat. Visual Neuroscience, 11, 10771082.CrossRefGoogle ScholarPubMed
Sanderson, K.J., Guillery, R.W., & Shackelford, R.M. (1974). Congenitally abnormal visual pathways in mink (Mustela vison) with reduced retinal pigment. Journal of Comparative Neurology, 154, 225248.CrossRefGoogle ScholarPubMed
Silveira, L.C.L., Heywood, C.A., & Cowey, A. (1987). Contrast sensitivity and visual acuity of the pigmented rat determined electrophysiologically. Vision Research, 27, 17191731.CrossRefGoogle ScholarPubMed
Ulrich, D.J., Essock, E.A., & Lehmkuhle, S. (1981). Cross-species correspondence of spatial contrast sensitivity functions. Behavioral Brain Research, 2, 291299.CrossRefGoogle Scholar
Wilson, H. R., Mets, M.B., Nagy, S. E., & Ferrera, V. P. (1988). Spatial frequency and orientation tuning of spatial visual mechanisms in human albinos. Vision Research, 28, 991999.CrossRefGoogle ScholarPubMed