September 18, 2012
New Technique Allows Scientists To Track Sperm Movements
Lee Rannals for redOrbit.com — Your Universe Online
A new imaging technique is allowing scientists to get more up close and personal than ever before with human sperm.
Imaging moving objects like sperm has been difficult to do through microscopes and other tools, so scientists developed the new technique to watch sperm like never before.
The new technique images the shadows of sperm using light of two different wavelengths produced from two different angles at the same time. The researchers are able to simultaneously track hundreds of sperm as they move.
Sperm were placed on a silicon sensor chip, with LED lights shining from different directions to track their movements, and plot their paths in 3D.
The team determined through the research that sperm actually swim in several different ways. The first is a generic head-forward trek, but the second way is a bit different. About 4 to 5 percent of sperm swim in curved, helical tracks, while a smaller percentage move in a more random fashion. The scientists found that each sperm doesn't just use one of these motions all the time, but instead switch from one to another.
Whether the sperm was swimming head-first or in the helical tracks depended on if they were in the fluid that surrounds semen in the testicles, or the fluid found in the fallopian tubes.
Currently, there is no finding of this study between the relationship of a sperm's swimming style, and whether or not it is healthy. However, future studies might reveal relationships between healthy semen and different swimming strokes through fluid.
The research was published in the journal Proceedings of the National Academy of Sciences.