Cells prepare themselves for winter. Carrie Straight 06.01.01 Some animals hibernate to survive in areas where the conditions are harsh, and food is scarce. During hibernation animals reduce their body temperature and their energy consumption. This allows them to live during these harsh times. So what happens to animals' cells when they are hibernating? Cold temperatures can hurt cell membranes. Some scientists wanted to figure out how the central nervous system cells and other tissues could deal with these changes in temperature. The temperature commonly changes from near freezing to 37 degrees C (degrees F). They analyzed cells from hibernating ground squirrels (Spermophilus tridecemlineatus). The scientists used microscopes to look at the cell structures during this time. They compared the structures during hibernation to after the squirrels woke-up from their long winter's nap. From looking at the cells before, during, and after hibernation, the researchers found gaps in the cytoplasm when the squirrels were hibernating. Upon looking closer at these gaps in the cellular fluid, the researchers actually found these gaps within a cellular organelle, the endoplasmic reticulum. These areas of the endoplasmic reticulum have no proteins compared the other areas of endoplasmic reticulum that have proteins. The researchers hypothesized that these areas free of proteins were probably created when the fat molecules in the cell change because of the cold. Azzam, Nabil A., John M. Hallenbeck, and Bechara Kachar. 2000. Membrane changes during hibernation. Nature 407: 317-318. ©2001 The Aurora Collection, Inc. All Rights Reserved. Site Development by: Interactive Multimedia. Inc.