Summary
Contrast thresholds were measured electrophysiologically on striate cortex in normal rats and in rats in which either the superior colliculi were removed bilaterally or unilaterally at 5 days of age, or one eye was removed on the day of birth. Despite the fact that the collicular ablation leads to the degeneration of more than half the retinal ganglion cells, contrast sensitivity was normal in this group, with the possible exception of sensitivity at very low spatial frequencies below 0.1 c/deg. The result is strong evidence that retinal ganglion cells which project to thalamus as well as to mid-brain escape the degenerative effects of neonatal mid-brain lesions. The contrast sensitivity of neonatally operated one-eyed rats was significantly and substantially better than that of normal rats tested monocularly. The increased sensitivity was greatest in the cortex ipsilateral to the remaining eye. This supernormal sensitivity is presumably related to the increase in the number of ganglion cells in the remaining eye, especially those projecting ipsilaterally from the temporal retina and which show a five-fold expansion of their terminal zone in the thalamus.
Similar content being viewed by others
References
Birch D, Jacobs GH (1979) Spatial contrast sensitivity in albino and pigmented rats. Vision Res 19: 933–937
Campbell FW, Maffei L (1970) Electrophysiological evidence for the existence of orientation and size detectors in the human visual system. J Physiol Lond 207: 635–653
Cowey A, Perry VJ (1979) The projection of the temporal retina in rats, studied by retrograde transport of horseradish peroxidase. Exp Brain Res 35: 457–464
Cowey A, Henken DB, Perry VJ (1982) Effects on visual acuity of neonatal or adult tectal ablation in rats. Exp Brain Res 48: 149–152
Dean P (1978) Visual acuity in hooded rats: effects of superior collicular or posterior neocortical lesions. Brain Res 156: 17–31
Dreher B, Potts RA, Ni SYK, Bennett MR (1984) The development of heterogeneities in distribution and soma sizes of rat retinal ganglion cells. In Stone J, Dreher B, Rapaport DH (eds) Development of visual pathways in mammals. Alan R Liss, New York, pp 39–58
Dreher B, Sefton AJ, Ni SYK, Nisbett G (1985) The morphology, number, distribution and central projections of class I retinal ganglion cells in albino and hooded rats. Brain Behav Evol 26: 10–48
Freeman RD, Bradley A (1983) Monocularly deprived humans: nondeprived eye has supernormal vernier acuity. J Neurophysiol 43: 1645–1653
Fukuda Y (1977) A three group classification of rat retinal ganglion cells: histological and physiological studies. Brain Res 119: 327–344
Fukuda Y, Sumitomo I, Hsaio C-F (1983) Effects of neonatal enucleation on excitatory and inhibitory organization of the albino rat lateral geniculate nucleus. J Neurophysiol 50: 46–50
Goodale MA, Milner AD (1982) Fractionating orientation behaviour in the rodent: the role of the superior colliculus. In: Ingle D, Goodale MA, Mansfield R (eds) Advances in the analysis of visual behaviour. MIT Press, Cambridge, pp 267–300
Heywood CA, Cowey A (1985) A comparison of the effects of superior collicular ablation in infant and adult rats. Exp Brain Res 59: 302–312
Heywood CA, Cowey A (1986) The nature of the visual discrimination impairment after neonatal or adult ablation of superior colliculus in rats. Exp Brain Res 61: 403–412
Heywood CA, Cowey A (1987) Effects on visual search of lesions of the superior colliculus in infant or adult rats. Exp Brain Res 65: 465–470
Hsiao CF, Fukuda Y (1984) Plastic changes in the distribution and soma size of retinal ganglion cells after neonatal monocular enucleation in rats. Brain Res 300: 1–12
Hughes A (1977) The refractive state of the rat eye. Vision Res 17: 927–939
Hughes A (1979) A schematic eye for the rat. Vision Res 19: 569–588
Innocenti GM (1979) Adult and neonatal characteristics of the callosal zone at the boundary between areas 17 and 18 in the cat. In I. Steele-Russell I, van Hof MW, Berlucchi G (eds) Structure and function of the cerebral commissures. Macmillan, London, pp 244–258
Jeffery G (1984) Retinal ganglion cell death and terminal field retraction in the developing rodent visual system. Dev Brain Res 13: 81–96
Jeffery G (1985) Early unilateral eye removal produces a regional gradient in soma sizes in the uncrossed projection from the remaining eye. Dev Brain Res 19: 155–159
Jeffery G, Perry VH (1981) Evidence for ganglion cell death during development of the ipsilateral retinal projection in the rat. Dev Brain Res 2: 176–180
Linden R, Perry VH (1982) Ganglion cell death within the developing retina: a regulatory role for retinal dendrites. Neuroscience 7: 2813–2827
Linden R, Perry VH (1983) Massive retinotectal projection in rats. Brain Res 272: 145–149
Linden R, Cowey A, Perry VH (1983) Tectal ablation at different ages in developing rats has different effects on retinal ganglion cell density but not on visual acuity. Exp Brain Res 51: 368–376
Linden R, Serfarty CA (1985) Evidence for differential effects of terminal and dendritic competition upon developmental neuronal death in the retina. Neuroscience 15: 853–868
Lund RD, Cunningham TJ, Lund JS (1973) Modified optic pathways after unilateral eye removal in young rats. Brain Behav Evol 8: 51–72
Martin PR (1986) The projection of different retinal ganglion cell classes to the dorsal lateral geniculate nucleus in the hooded rat. Exp Brain Res 62: 77–88
Montero VM, Rojas A, Torrealba F (1973) Retinotopic organization of striate and peristriate visual cortex in the albino rat. Brain Res 53: 197–201
Perry VH (1981) Evidence for an amacrine cell system in the ganglion cell layer of the rat retina. Neuroscience 5: 931–944
Perry VH, Cowey A (1979) Changes in the retino-fugal pathways following cortical and tectal lesions in neonatal and adult rats. Exp Brain Res 35: 97–108
Perry VH, Cowey A (1982) A sensitive period for ganglion cell degeneration and the formation of aberrant retino-fugal connections following tectal lesions in rats. Neuroscience 3: 583–594
Perry VH, Linden R (1982) Evidence for dendritic competition in the developing retina. Nature 297: 683–685
Powers MK, Green DG (1978) Single retinal ganglion cell responses in the dark-reared rat: grating acuity, contrast sensitivity and defocusing. Vision Res 18: 1533–1539
Reese BE (1986) The topography of expanded uncrossed retinal projections following neonatal enucleation of one eye: differing effects in dorsal lateral geniculate nucleus and superior colliculus. J Comp Neurol 250: 8–32
Sakai M, Fumio Y, Yukinobu I (1983) Evoked potentials in the visual cortex as modified by enucleation of one eye in the albino rat. Physiological Psychol 11: 141–146
Silveira LCL, Heywod CA, Cowey A (1987) Contrast sensitivity and visual acuity of the pigmented rat determined electrophysiologically. Vision Res (in press)
Stone J (1981) The whole mount handbook: a guide to the preparation and analysis of retina whole mounts. Maitland Publications, Sydney
Weibel ER (1969) Stereological principles for morphometry in electron microscopic cytology. Int Rev Cytol 26: 235–301
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Heywod, C.A., Silveira, L.C.L. & Cowey, A. Contrast sensitivity in rats with increased or decreased numbers of retinal ganglion cells. Exp Brain Res 70, 513–526 (1988). https://doi.org/10.1007/BF00247599
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00247599