"Proper migration of neurons during development is essential for normal development of the cerebral cortex and its function," said Pasko Rakic, M.D., chair of the Department of Neurobiology and senior author of the study. "We have observed that a small but significant number of neurons in the mouse embryonic brain do not migrate to their proper positions in the cerebral cortex following prolonged and frequent exposure to ultrasound."
Neurons in mammals multiply early in fetal development and then migrate to their final destinations following an inside-to-outside sequence. The destination defines the neurons' connectivity and function. It has been reported earlier by others that abnormal cortical function may result when this process is grossly altered by genetic or environmental factors such as alcohol and drugs.
The study reported on August 7 is believed to be the first to look at the possible effect of ultrasound waves (USW) on neuronal migration in mice at a late stage of embryonic brain development, when the migratory pathways are the longest and may be most vulnerable. The Yale team injected more than 335 fetal mice at embryonic day 16 with special markers to track neuronal development. Exposure to USW for 30 minutes or longer caused a small but statistically significant number of neurons to remain scattered within inappropriate cortical layers and/or in the adjacent white matter.
"The magnitude of dispersion of labeled neurons was highly variable but increased with duration of exposure to ultrasound waves," Rakic said. "These findings suggested the desirability of further work in this area. We do not have any evidence ourselves that USW cause behavioral effects in mice or have any effect on the developing human brain."
"Therefore," he continued, "I want to emphasize that our study in mice does not mean that use of ultrasound on human fetuses for appropriate diagnostic and medical purposes should be abandoned. On the contrary: ultrasound has been shown to be very beneficial in the medical context. Instead, our study warns against its non-medical use. We intend to conduct further research, which will focus on non-human primates, to see if a similar effect is occurring in the developing larger brains, which are more similar to humans. Those upcoming studies should give us information that will be more directly applicable to uses of USW in humans."
Jacqueline Weaver | EurekAlert!
Flavins keep a handy helper in their pocket
25.04.2018 | University of Freiburg
Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
25.04.2018 | Physics and Astronomy
25.04.2018 | Physics and Astronomy
25.04.2018 | Information Technology