Modification of Retinal Function by Hypothermia and Hyperthermia

  • Chon, Young-Shin (Department of Physiology, School of Medicine,Gyeongsang National University) ;
  • Kim, You-Young (Department of Biochemistry,College of Natural Sciences, Kyungpook National University)
  • Published : 2000.12.01

Abstract

Temperature-dependent electroretinogram responses were investigated in the dark adapted bullfrog eyes within the physiological temperature range 0-40$\^{C}$. In hypothermic process(25→0→25$\^{C}$), the amplitude of b-and c-wave decreased with lowering the temperature again. Both b-wave amplitude and threshold responses were maximal around 15$\^{C}$ during the temperature increment. Upon warming to room temperature again (25$\^{C}$), the b-wave amplitude was approximately doubled as compared to that of control without temperature changes. During the hyperthermic process (25→40→25$\^{C}$), however, the responses decreased with warming, and the wave amplitude failed to recover by cooling to 25$\^{C}$ again. As describe above, the recoveries of ERG in both processes show the striking difference. The hypothermia induces the amplification of the b-wave, that is, enhances the retinal function with the temperature recovery toward room temperature. While the hypertherima produces the decrease of the b-wave even though recovered to room temperature, which indicates an irreversible retina. The morphological alteration is shown both hypothermic and hyperthermic process, such as an appearance of large vacuoles and degenerating outer segments, more intense in hyperthermia, similar to light induced damage.

Keywords

References

  1. The Electroretinogram:Its Components and Their Origin.Vision Res. v.8 Brown;K.T.
  2. J.Neurophysiol. v.33 Intracellular responses of the Muller(glial)cells of mudpuppy retina:their relation to b-wave of the electroretiongram. Miller;R.F.;Dowling;J.E.
  3. Proc.Natl.Acad.Sci. v.87 K?-evoked Muller cell depolarization generates b-wave of electroretinogram in toad retina. Wen;R.;Oakley;B.
  4. Invest.Ophthalmol.Vis.Sci. v.36 Hyperthermia Accelerates Retinal Light Damage in Rats. Organisciak;D.T.;Darrow;R.M.;Noell;W.K.;Blanks;J.C.
  5. Arch Ophthalmol. v.109 no.8 Effect of Temperature on Electroretinograph Readings During Closed Vitrectomy in Human. Horiguchi M.;Miyake;Y.
  6. Am.J.Ophthalmol. v.109 Clinical and histologic effects of extreme intraocular hypothermia. Zills;J.D.;Chandler;D.Machemer;R.
  7. American Journal of Ophthalmology v.102 Temperature-Dependent Light Damage to the Retina. Rinkoff;J.;Machemer;R.;Hida;T.;Chandler;D.
  8. Vision Research v.25 Temporal transfer and nonlinearity properties of turtle ERG:Tuning by temperature,pharmacology,and light intensity. Adolph;A.R.
  9. Acta Ophthalmologica v.62 Temperature effects on the electroretinogram of the isolated carp retina. Armington;J.C.;Adolph;A.R.
  10. Vision Res. v.36 The Effect of In Vivo Retinal Cooling on the Electroretinogram of the Rabbit. Lachapelle;P.;Benoit;J.;Guit;P.
  11. Documenta Ophthalmologica v.39 The function of the retina in teh perfused eye. Niemeyer;G.
  12. The Functional Organization of teh Compound Eye Hormonal regulation of retinal pigment migration in crustaceans. Kleinholz;L.H.
  13. Experinmental eye research v.65 Protective effects of local hypothermia in vitrectomy under fluctuating intraocular pressure. Tamai;K.;Toumoto;E.;Majima;A.
  14. Animal physiology:Mechanisms and adaptations. Animal energetics and temperature relations. Eckert;R.;Randall;D.;Augustine;G.
  15. Invest Ophthalmol Vis Sci. v.29 Effects on retinal adhesion of temperature,cyclic AMP,cytochalasin,and enzymes. Yoon;Y.H.;Marmor;M.F.
  16. Invest Ophthalmol Vis Sci. v.29 Pigment adherence as a measure of retinal adhesion:Dependence on temperature. Endo;E.G.;Yao;X.Y.;Marmor;M.F.
  17. Neurochemical Research v.15 Induction of a heat shockgene(hsp70)in rabbit retinal ganglion cells detected by in situ hybridization with plastic-embedded tissue. Masing,T.E.;Rush;S.J.;Brown;I.R.
  18. J.Neurosci.Res. v.38 Induction of heat shock(stress)protein 70 and its mRNA in the normal and light-damaged rat retina after whole body hyperthermia. Tytell;M.;Barbe;M.F.;Brown I.R.
  19. Heat Shock Proteins in the Nervous System Heat Shock Proteins in the Retina and Optic Nerve. Tytell;M.