AP Biology class blog for discussing current research in Biology

Tag: Senses

How Ground Squirrels Are Bracing For The Cold

As we enter the heart of winter, puffy coats, hats, and gloves make it out of our closets to protect us from the frigid air. While we trudge along shivering, the ground squirrel lives happily in the cold weather, resistant to the low temperatures.

The Phenomenon:

A new study shows that when the ground squirrel wakes from hibernation, it is less sensitive to the cold than its non-hibernating relatives. Why? A cold-sensing protein, TRPM8, in the sensory nerve cells is partly responsible for the amazing phenomenon.

The Evidence:

In an experiment conducted with mice (non-hibernating), ground squirrels, and Syrian hamsters (hibernating animals closely related to the ground squirrel), the animals were given the choice between a hotter plate and a colder plate. Whereas the mice gravitated toward the hot plate, the ground squirrel and Syrian hamster did not react to the cold temperature of the plate until it dropped below 10 degrees Celsius.

The Biology:

Part of the squirrel’s and hamster’s intolerance to cold has to do with the TRPM8 protein. TRPM8 is a cold-sensing protein that sends a signal to the brain when something is too cold. Researchers turned to the gene responsible for turning on the TRPM8 protein to find the differences between a ground squirrel and a rat. They found a chain of six amino acids in the squirrel gene that caused the adaptation to cold. When they switched that section with one from a rat, the squirrel was more sensitive to the cold.

It is quite amazing that scientists can extract and switch such small portions of DNA to find the exact cause of a trait. What else do you think this technology could be used for?

The Effect on Life:

Tolerance to cold may help the squirrel and hamster transition from an awake state to hibernation state. This is true because if an animal senses or feels cold, it will expend a lot of energy trying to warm itself up. This process counters they physiological changes needed to transition into hibernation, a state of low metabolic activity. Hence, since the hamster and squirrel don’t sense the cold, it will be easier to hibernate.

Further Research:

There is still a lot unknown about the TRPM8 protein and ground squirrel temperature sensitivities. It is believed that TRPM8 is only a part of their intolerance to cold. Furthermore, the structure and function of TRPM8 is still being studied and could lead to more breakthroughs. Want to learn more about ground squirrels, hibernation, or the TRPM8 protein? Click here to read the full article!

Tasting Colors?!

Credit: Carly Bodnar

Last year while doing a practice SAT reading section, I came across a story about a condition called synesthesia. If you have never heard of it before, you’re not alone. Synesthesia is a very rare, sense-mixing condition in which people taste colors or see smells. Sounds crazy, right? According to studies, 3% of the world population claim that they experience some form of synesthesia. I couldn’t believe it! I didn’t understand how people could taste and see intangible things.

A recent study shows that there is a pattern among people who have the condition that close family members have similarly entangled senses. Scientists have examined several genes to see which ones contribute to the phenomenon. Scientists hope that the uncovering of the condition’s genetic basis might reveal why it occurs and potentially help develop cures for similar neurological diseases.

The study, led by neuroscientist David Eagleman, studied a region of chromosome 16, the chromosome believed to hold the gene responsible for synesthesia. Eagleman and his colleagues believe that a defect in this gene may blend connections in the brain, leading to insufficient regulation of the brain’s neural bridges. David Brang from the University of California, San Diego explains, “It could be that everyone is born with global connectivity in the brain, and over time most undergo a refining process.” Another theory proposes that synesthesia is caused by a shift in the brain’s balance of chemicals. This hypothesis is supported by the fact that people can have synesthetic experiences if they take hallucinogens.

Eagleman believes that the continued study of synesthesia could more clearly illustrate how genetic changes affect changes in brain function. Finding more information about synesthesia can help uncover how different brain areas interact with each other. The discovery of neurological networking problems could also help find cures for or advancements in other degenerative neurological and genetic diseases. So for those of you who didn’t believe that such a condition existed, it does! Keep in mind, though, that these types of diseases often have genetic origins, another reason why there is not that much information on these obscure diseases. However, at a time when advancements and discoveries in genetics are so prevalent, Eagleman is confident that more information about this condition will be uncovered soon. Remember, next time you are doing a SAT reading section, don’t forget about the information given in those stories, they could give you insight into potential scientific discoveries!

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