Superficial Extensor MRO - Sensory Adaption

The superficial extensor muscle in the crayfish tail is responsible for stretching the tail back to straight after an escape response flex by the deep flexor muscle. In order to determine the location of the tail, sensory neurons are embedded in the muscle tissue and change their firing rate based on physical stretch of the extensor muscle membrane. If the tail is pulled to a fixed stretch, the muscle receptor organ (MRO) neurons will adapt to a constant rate of fire that is much less than the initial rate of fire when pulled to the peak.

This adaption rate has analogies in senses such as smell and vision and touch. Most sensory systems are designed to detect changes in the outside world. Sensory adaption is an exponential feedback process similar to cruise control in a car.

This example application illustrates rate detection and multi-parameter clustering other than a parameter vs time to reveal interesting information about a system.

Raw Data Files

• MRO-ADAPT.mat - 20 second recording of a tail strech and neuron adaption. -- .wav
• adapt-only-results.txt - Only the decaying portion of the rate curve for curve fitting outside of g-PRIME

This data set contains one spiking neuron adapting to a sensory stimulus (in this case a tail stretch). Selecting "rate" from the "y-axis metric" display in the lower events analysis panel illustrates the rate of adaption of this specific sensory neuron.

Instead of displaying rate versus time, now, energy density of a spike versus interval since previous spike is illustrated. In this data representation, one can see the response of individual spikes in this neuron to inter-spike-interval. The shorter the interval between spikes, the smaller the subsequent spike is in amplitude. This amplitude saturates at a given inter-spike interval. This illustrates a recovery period for the neuron that inhibits full energy of the action potential. Note that these data points illustrate values acquired after the tail had stopped moving so the change in amplitude is not a funciton of the electrode attaching to the nerve differently. The effect is small but noticable.