The aim of this experiment was to characterize the physiological properties of cat retinal ganglion cells that project to the suprachiasmatic nucleus (SCN). Retrogradely labeled SCN-projecting ganglion cells were recorded extra-cellularly in vitro. For the first time, this study provides crucial information on visual response properties of ganglion cells in the entrainment circuitry. All recorded cells gave sustained responses (n = 9). Although most of the cells (n =8) had an “on” center receptive field, one cell showed “on-off” center receptive field properties. The range of receptive field sizes was 2 to 5 deg. For most of the cells tested, the spectral wavelength that evoked peak responses was 500 nm (3 out of 5 cells). All recorded cells (n = 9) preferred still or extremely slow-moving stimuli (3.3 deg/s). These results indicate that cat SCN-projecting cells receive inputs from conventional photoreceptors. The hypothesis that both conventional and cryptochromic photoreceptors are involved in transferring photic signals is discussed.
Ames A III and Nesbett FB (1981)In vitro retina as an experimental model of the central nervous system. J Neurochem37:867-877.
2.
Boycott BB and Kolb H (1973) The connections between bipolar cells and photoreceptors in the retina of the domestic cat. J Comp Neurol148:91-114.
3.
Cashmore AR, Jarillo JA, Wu YJ, and Liu D (1999) Cryptochromes: Blue light receptors for plants and animals. Science284(5415):760-765.
4.
Chen B and Pourcho RG (1995) Morphological diversity and glutamate immunoreactivity of retinal terminals in the suprachiasmatic nucleus of the cat. J Comp Neurol361(1):108-118.
5.
Czeisler CA, Shanahan TL, Klerman EB, Martens H, Brotman DJ, Emens JS, Klein T, and Rizzo JF III (1995) Suppression of melatonin secretion in some blind patients by exposure to bright light. N Engl J Med332(1):6-11.
6.
Freedman MS, Lucas RJ, Soni B, von Schantz M, Munoz M, David-Gray Z, and Foster R (1999) Regulation of mammalian circadian behavior by non-rod, non-cone, ocular photoreceptors. Science284(5413):502-504.
7.
Groos GA and Mason R (1978) Maintained discharge of rat suprachiasmatic neurons at different adaptation levels. Neurosci Lett8:59-64.
8.
Groos GA and Mason R (1980) The visual properties of rat and cat suprachiasmic neurones. J Comp Physiol [A]135:349-356.
9.
Klein D, Moore RY, and Reppert S (1991)Suprachiasmatic Nucleus: The Mind's Clock. Oxford University Press, Oxford, UK.
10.
Kolb H, Nelson R, and Mariani A (1981) Amacrine cells, bipolar cells and ganglion cells of the cat retina: A Golgi study. Vision Res21:1081-1114.
11.
Lincoln DW, Church J, and Mason C (1975) An Electro-physiological activation of suprachiasmatic neurones by changes in retinal illumination. Acta Endocrinol Suppl199: 184-184.
12.
Lucas RJ and Foster RG (1999) Photoentrainment in mammals: A role for cryptochrome?J Biol Rhythms14(1):4-10.
13.
Lucas RJ, Freedman MS, Munoz M, Garcia-Fernandez JM, and Foster RG (1999) Regulation of the mammalian pineal by non-rod, non-cone, ocular photoreceptors. Science284:505-507.
14.
Meijer JH, Groos GA, and Rusak B (1986) Luminance coding in a circadian pacemaker: The suprachiasmatic nucleus of the rat and hamster. Brain Res382:109-118.
15.
Meijer JH and Rietveld WJ (1989) Neurophysiology of the suprachiasmic circadian pacemaker in rodents. Physiol Rev69:671-707.
16.
Meijer JH, Watanabe K, Schaap J, Albus H, and Detari L (1998) Light responsiveness of the suprachiasmatic nucleus: Long-term multiunit and single-unit recordings in freely moving rats. J Neurosci18:9078-9087.
17.
Miller JD, Morin LP, Schwartz WJ, and Moore RY (1996) New insights into the mammalian circadian clock. Sleep19:641-667.
18.
Miyamoto Y and Sancar A (1998) Vitamin B2-based blue light photoreceptors in the retinohypothalamic tract as the photoactive pigments for setting the circadian clock in mammals. Proc Natl Acad Sci USA95(11):6097-6102.
19.
Moore RY (1983) Organization and function of a central nervous system circadian oscillator: The suprachiasmatic hypothalamic nucleus. Fed Proc42:2783-2789.
20.
Moore RY, Speh JC, and Card JP (1995) The retinohypothalamic tract originates from a distinct subset of retinal ganglion cells. J Comp Neurol352:351-366.
21.
Morin LP (1994) The circadian visual system. Brain Res Rev67:102-127.
22.
Murakami DM, Miller JD, and Fuller CA (1989) The retino-hypothalamic tract in the cat: Retinal ganglion cell morphology and pattern of projection. Brain Res482:283-296.
23.
Nelson GE and Takahashi JS (1991) Sensitivity and integration in a visual pathway for circadian entrainment in the hamster (Mesocricetus auratus). J Physiol439:115-145.
24.
Pickard GE (1980) Morphological characteristics of retinal ganglion cells projecting to the suprachiasmatic nucleus: A horseradish peroxidase study. Brain Res183(2):458-465.
25.
Pickard GE (1982) The afferent connections of the suprachiasmatic nucleus of the golden hamster with emphasis on the retinohypothalamic projection. J Comp Neurol211(1):65-83.
26.
Provencio I, Wong S, Lederman AB, Argamaso SM, and Foster RG (1994) Visual and circadian responses to light in aged retinally degenerate mice. Vision Res34(14):1799-1806.
27.
Pu M (1999) Dendritic morphology of cat retinal ganglion cells projecting to suprachiasmatic nucleus. J Comp Neurol414:267-274.
28.
Pu M and Berson D (1992) A method for fast and stable intracellular staining of retinal ganglion cells. J Neurosci Methods41:45-49.
29.
Pu M, Pen T, and Berson D (1994) Structure and function of ganglion cells projecting to the cat's geniculate wing: An in vitro study. J Neurosci14:4338-4358.
30.
Rusak B and Zucker I (1979) Neural regulation of circadian rhythms. Physiol Rev59:449-526.
31.
Snider RS and Niemer WT (1961)A Stereotaxic Atlas of the Cat Brain. University of Chicago Press, Chicago.
32.
Thresher RJ, Vitaterna MH, Miyamoto Y, Kazantsev A, Hsu DS, Petit C, Selby CP, Dawut L, Smithies O, Takahashi JS, and Sancar A (1998) Role of mouse cryptochrome bluelight photoreceptor in circadian photoresponses. Science282(5393):1490-1494.
