Growth cone collapse and neurite retractions: an approach to examine X-irradiation affects on neuron cells.
The growth cone is a structure at the terminal of a neurite that plays an important role in the growth of the neurite. The growth cone collapse assay is considered to be a useful method to quantify the effects of various factors on nerve tissue. Here, we investigated the effect of x-irradiation on growth cones and neurites and also the comparative radiosensitivity of different neurons. Dorsal root ganglia and sympathetic chain ganglion were isolated from day-8 and -16 chick embryos and cultured for 20 h. Neurons were then exposed to x-irradiation and morphological changes were quantitatively evaluated by growth cone collapse assay. Cell viability was examined using TUNEL and WST-1 assays. The results showed that radiation induced growth cone collapse and neurite retraction in a time- and exposure-responsive manner. Growth cone collapse, apoptosis and WST-1 assays showed that no significant difference between the neurons throughout the study period (p > or = 0.5) after irradiation. Both types of day-8 neurons were more radio-sensitive than day-16 neurons (p < or = 0.05). The time course of the growth cone collapse was significantly correlated with the apoptotic and cell viability responses at different irradiation doses. Growth cone collapse may represent a useful marker for assaying the effect of x-irradiation on normal cell neurons.
Department of Radiation Oncology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, Japan.
Wael S
WS
Al-Jahdari
Yoshiyuki
Y
Suzuki
Yukari
Y
Yoshida
Shin-ei
SE
Noda
Katsuyuki
K
Shirai
Shigeru
S
Saito
Fumio
F
Goto
Takashi
T
Nakano
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D004307:Dose-Response Relationship, Radiation; D020439:Growth Cones / Q000502:physiology / Q000528:radiation effects* / Q000648:ultrastructure*; D016501:Neurites / Q000502:physiology / Q000528:radiation effects* / Q000648:ultrastructure*; D009474:Neurons / Q000502:physiology / Q000528:radiation effects* / Q000648:ultrastructure*; D011829:Radiation Dosage; D014965:X-Rays