Grasshopper Mice Are Numb to the Pain of the Bark Scorpion Sting

A recent study conducted by Ashlee Rowe, Assistant Professor of Zoology at Michigan State, investigated the effect of the scorpion toxin on the Grasshopper Mice. The deadly sting of this scorpion for a mammal of this size and bigger is well documented; however, the Grasshopper mice appears to be unaffected by the scorpions sting.  Scientists began conducting controlled trials with the mice and the scorpion. This video, "Mouse v Scorpion" illustrates a portion of the experiment.  It can be viewed on YouTube at:

                                   http://youtube/3S4sMBFBZ0M 

 

            After analysis of this trial, scientists needed to test the mice to discover what caused the absence of pain response. They injected their paw with a small dose of venom and nontoxic saline to see the response. The response was that the mice came up with less pain from the venom then saline. When they observed this, they examined pain neurons that have a couple of different sodium channels, called 1.7 and 1.8; the channels, shows that when toxins bind to 1.7 channels, the channels open, sodium flows in and the pain neuron fires.  The research discovered that channel 1.8 in the grasshopper mice has an amino acid to block the pain of scorpion stings that are different from mammals.  The scorpion toxin binds to one of these amino acids to block the activation of channel 1.8 and thus inhibit the pain response. 

 

This research will be the start of the development of new analgesics for humans in the future. Hopefully, it will lead to relief for many people.

http://www.sciencedaily.com/releases/2013/10/131024143422.htm 

http://www.utexas.edu/news/2013/10/24/grasshopper-mice-bark-scorpion/

 

"Painful Touch" Proteins

Recent developments have been made on specific proteins in the outer membranes that correspond to pressure, pain, heat, cold, and other stimuli.  Based on research evidence, presented in an article in Science Daily, a specific family of sensory nerve proteins, piezo proteins have been discovered to to be essential to the sensation of painful touch.  The piezo protein is an exceptionally strong candidate for pressure-transducing ion channel proteins in mammals.  Experiments in the new study are conducted on fruit flies, who also express the piezo protein, which provide a model system for the sensory nervous system in mammals.

Patapoutian, a scientist, has a laboratory that specializes in the study of sensory ion channel proteins.  In the first study conducted within the new study on the piezo protein in Patapoutian's lab it was confirmed that piezo proteins are indeed very large ion channel proteins.  The second study conducted within the new study was done on Drosophila fruit flies.  A line of genetically engineered fruit flies were created without the piezo protein.  The larvae of these flies showed a loss of responsiveness to mechanical stimuli-that should cause pain, yet responded normally to other kinds of stimuli.  Some of the larvae born without the piezo protein were reinstated with dpiezo.  These larvae demonstrated normal sensitivity to strong pressure.

Although scientists believe this protein very likely contributes to pressure-transduction, future studies on roles of piezo proteins in sensing sound, blood pressure and related stimuli that press and/or stretch cell membranes will be conducted.  This is a huge advancement in the understanding of stimuli and how we receive outside messages and transmit them to the brain.  I find it very interesting that the understanding of how the human body works advances over time and never ceases to a halt.