title: Once the Light Touch to the Brain: Cytotoxic Effects of Low-Dose Gamma-Ray, Laser Light, and Visible Light on Rat Neuronal Cell Culture.
abstract: OBJECTIVE
  We aimed to evaluate the effects of gamma-ray, laser light, and visible light, which neurons are commonly exposed to during treatment of various cranial diseases, on the viability of neurons.
  
  
  METHODS
  Neuronal cell culture was prepared from the frontal cortex of 9 newborn rats. Cultured cells were irradiated with gamma-ray for 1-10 min by (152)Eu, (241)Am, and (132)Ba isotopes, visible light for 1-160 min, and laser light for 0.2-2 seconds. The MTT tetrazolium reduction assay was used to assess the number of viable cells in the neuronal cell cultures. Wavelength dispersive X-ray fluorescence spectrometer was used to determine Na, K, and Ca levels in cellular fluid obtained from neuronal cell culture plaques.
  
  
  RESULTS
  Under low-dose radiation with (152)Eu, (241)Am, and (132)Ba isotopes, cell viability insignificantly decreased with time (p>0.05). On the other hand, exposure to visible light produced statistically significant decrease in cell viability at both short- (1-10 min) and long-term (20-160 min). Cell viability did not change with 2 seconds of laser exposure. Na, K, and Ca levels significantly decreased with gamma-ray and visible light. The level of oxidative stress markers significantly changed with gamma-ray.
  
  
  CONCLUSIONS
  In conclusion, while low dose gamma-ray has slight to moderate apoptotic effect in neuronal cell cultures by oxidative stress, long-term visible light induces remarkable apoptosis and cell death. Laser light has no significant effect on neurons. Further genetic studies are needed to clarify the chronic effect of visible light on neuronal development and functions.
authors.affiliation: Department of Neurosurgery, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Murteza
authors.initials: M
authors.lastname: Cakir
authors.affiliation: Department of Neurosurgery, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Colak
authors.affiliation: Department of Neurosurgery, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Cagatay
authors.initials: C
authors.lastname: Calikoglu
authors.affiliation: Department of Pharmacolgy, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Numan
authors.initials: N
authors.lastname: Taspinar
authors.affiliation: Department of Biophysics, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Mustafa Erdem
authors.initials: ME
authors.lastname: Sagsoz
authors.affiliation: Department of Neurosurgery, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Hakan Hadi
authors.initials: HH
authors.lastname: Kadioglu
authors.affiliation: Department of Pharmacolgy, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Hacimuftuoglu
authors.affiliation: Department of Physics, Atatürk University School of Educating, Erzurum, Turkey.
authors.forename: Sabriye
authors.initials: S
authors.lastname: Seven
keywords: Neuron; apoptosis; cell culture; cytotoxicity; laser light; radiation