Biology colloquium delves into the science of touch

At the Science Colloquium on Tuesday, Nov. 5, Professor Douglas Martin explored the science behind the sensation of touch and discussed his ongoing project to delve deeper into the topic.

In his lecture, Martin spoke about “mechanosensation,” or the mechanical stimulus involved with the sensation of touch. For the past two years, Martin has been working with students to answer the question of whether or not microtubule stiffness is linked to the transmission of mechanical stimuli along the microtubule. This question arose from Martin’s examination of experiments implemented by other universities about the science behind touch.

“I think that there are a lot of different answers when it comes to how we react to physical stimuli and what we experience when it comes to touch,” Martin said.

Microtubules come in large and small sizes. Large microtubules are often found in nerve cells, while smaller ones are found throughout the rest of the body. This was proven with an experiment on C. elegan worms that were poked with eyelashes to test their response to touch. It was found that mutant worms with small microtubules had no feeling of touch.

In his experiment, Martin was working under the assumption that the large microtubules were stiffer than the smaller ones. Working with this assumption, Martin designed an experiment that used kinesin “hands” to push on the microtubules, making it bend like “crowd surfing.” Martin knew the range of the force the “hands” would place on the microtubule and got bending to occur.

However, he faced the problem that the number of kinesin “hands” that could be seen were too small. Martin increased the precision factor by 10 and is currently working on this part of the experiment.

After receiving a grant from the National Science Foundation, Martin is now trying to get a longer distance “crowd surf” for his microtubules to get better statistics from the data.

“The next step is to take apart the apparatus we built and build a new one,” Martin said.

The audience at the lecture included teachers and students alike. Professor Brian Piasecki said that he was impressed with Martin’s explanation of everything in an accessible way.  “His use of props, imagery and narration was very helpful and informative,” Piasecki said.

Sophomore Terese Swords, was among the handful of students present at the lecture. For Swords the interest in the lecture stemmed from the use of C. elegans in the experiment.

“I am currently doing research on sensory cilia in C. elegans with Brian Piasecki,” Swords said. “I thought it would be interesting to see if any of the lecture related to my research.”

Martin said he has been interested in touch for many years. Now, with the grant, he will be able to do more research in the field of mechanosensation and continue testing his hypothesis about the stiffness of microtubules in nerve cells.

“This experiment is […] adding to our understanding of how we lose touch sensitivity from certain diseases,” Martin said.