Crabs Helping Us Understand Motor Control



Anyone who has ever lived near Baltimore knows the area is obsessed with crab. After living here for 6 years, I thought I had learned all there was to about crabs. But a group from the University of Missouri showed me how much crabs can teach us about motor control.

Adam Northcutt’s poster, presented by Brian Lane show that cancer borealis (crabs) have a small number of motor neurons, and each motor neuron is simple to consistently identify from animal to animal. Using this they were able to collect the same set of motor neurons from several animals and collect mRNA from these cells. They then created ion channel profiles to expand what we new about unique mRNA markers for each motor neuron. From there they plotted 2 mRNAs on each axis and plotted their relative values to each other, creating a R value for each. Plotting these R values on a heat map for each mRNA can create cell type specific mRNA correlation patterns. There is now a way to identify which motor neuron you are looking at by mRNA values.

These mRNA values are activity dependent. TTX and TEA both block correlation. Furthermore, they found you don’t have to look at all mRNA values to distinguish between different motor neurons such as the cardiac motor neuron and the stomatogastric ganglion. They found innexin (the invertebrate version of connexin) was robust even with TTX applications. This could lead to simple identification of motor neurons in more complex systems.

So the next time my friends and I are enjoying fresh steamed crabs, I’ll have a new appreciation for not just how delicious they taste, but what they are teaching us about the nervous system.