RESUMEN
The effect of magnetic resonance (MR) exposure on the proliferation and migration of motoneurons was examined in chick embryos. Embryos were exposed in ovo to a static magnetic field of 1.5 T for 6 hours and to 64-MHz radio-frequency field pulses and a switched magnetic field gradient with an amplitude of 0.6 G/cm for 4 hours. For cell proliferation studies, embryos were exposed to MR fields during the developmental stage at which motoneuron proliferation is most active. For cell migration studies, embryos were exposed to MR fields at the developmental stage just before lateral motoneuron migration. The results show that the birth dates, migration, and proliferation of lateral motoneurons were unaffected by the MR exposure conditions in this study.
Asunto(s)
Imagen por Resonancia Magnética , Neuronas Motoras/citología , Anomalías Inducidas por Radiación , Animales , Autorradiografía , División Celular/efectos de la radiación , Movimiento Celular/efectos de la radiación , Radioisótopos de Cesio/efectos adversos , Embrión de Pollo , Campos Electromagnéticos , Rayos gamma/efectos adversos , Magnetismo , Mitosis/efectos de la radiación , Neuronas Motoras/metabolismo , Neuronas Motoras/efectos de la radiación , Médula Espinal/anomalías , Médula Espinal/citología , Médula Espinal/embriología , Médula Espinal/efectos de la radiación , Timidina/metabolismo , TritioRESUMEN
The effect of ultrasound exposure on proliferation and migration of motoneurons was examined in chick embryos. Using an egg preparation which minimizes ultrasonic reflections and standing wave generation, chick embryos were exposed to ultrasound in ovo for 10 min at an intensity of 2 W/cm2 Spatial Average, Temporal Average (SATA) with a frequency of 1.1 MHz pulsed at 2 kHz, and a pulse width of 75 microseconds. For cell proliferation studies, embryos were irradiated at the developmental stage of the most active lateral motoneuron proliferation. For cell migration studies, embryos were irradiated at the developmental stage just prior to lateral motoneuron migration. Our results show that the birthdates, migration and proliferation of lateral motoneurons are unaffected by the ultrasound exposure parameters used in this study.