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Physiology Recording & Identification of Multiple Events
Gus K. Lott III, Ph.D.
Software Oscilloscope & Data Logging |
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Physiology Recording & Identification of Multiple Events
Gus K. Lott III, Ph.D.
Software Oscilloscope & Data Logging |
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There is a small tonic offshoot of the ventral nerve chord in the crayfish that carries 6 motor neurons that innervate the superficial flexor muscle in each half segment of the crayfish tail. The nerve is tonically active (no stimulus). The neurons in the nerve changes firing behavior in response to both swimmeret (small appendages on underside) and telson (tail fan) stimulation. This nerve innervates a sheath of superficial flexor muscles responsible for control of posture. The nerves innervate these muscles in a multi-terminal fashion (as opposed to single terminal neuromuscular innervation in mammals) and is thus a good model for multi-terminal nerves in the brain (easily accessible). This system is a model for many exercises in the crawdad lab educational project. This example application of g-PRIME illustrates variation in the third nerve neuron firing rates in three different stimulus regimes.
Raw Data Files
 This figure illustrates the 6 units with 6 distinct energy densities. The distinct levels are labeled with N1-N6 (these labels will not appear in your window). This is the behavior of the system in a saline solution without external stimulation. Exact details as to how to produce this graphic are shown below.
 Clusters can be visualized using multiple parameters from the analysis display mode. This can aid in group extraction using the polygon tools at the bottom of the analysis window. In this case, many of the outlying points indicate overlaps in the selected window region.
 This figure illustrates swimerette stimulation in the crayfish tail which demonstrates an inhibition of neurons 1 through 4 and neuron 6 and an upregulation of neuron 5 (known to be the inhibitory neuron in the bundle). It illustrates a partial inhibition of neurons 1-4 and a total inhibition of neuron 6. Procedure for diplay is the same as above, just load swimerette6nerves2.daq instead of the passive file.
 Analysis on the file "telson6nerves1.daq." Here is a dramatic upregulation of activity relative to the passive stimulus regime in response to stimulation of the crayfish tail fan. Each of these data files was taken from the same preparation. The large spike at the beginning of the data series corresponds a static discharge into the solution as I moved to stimulate the tail fan. This is a good illustration of when stimulus began. You can see a few seconds later where the 6th neuron recruits in response to the tail fan stimulation and there is a general rate increase (visually) in all neurons except for the 5th neuron (inhibitor).
  
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