Submitted by: Submitted by Englishhelp
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Category: Science and Technology
Date Submitted: 10/24/2011 02:06 AM
Introduction
The main goal of this lab was to record a series of action potentials from a single cockroach leg (species: P. Americana) and use the recordings to understand the concept of sensory transduction. The concept of sensory transduction is basically converting one form of stimuli to another. This is done by the sensory neurons located under the spine in this particular lab. To encode this information, the nervous system must recognize the sensory stimulus. There are two basic properties of a stimulus: modality and intensity. Modality is encoded by the pathway of the stimulus and intensity is encoded by the frequency of action potentials. The two types of responses we looked at in lab were phasic (adapt) and tonic (do not adapt). To record the response of a cockroach spine, we inserted a punctured the leg with an insect pin and used a probe to push a spine to generate a stimulus. The data was recorded in Chart.
Methods
Refer to lab 2, pages 6-9 in the lab manual.
Results
Figure 1: For the spontaneous activity of the cockroach leg, we attached the leg to two insect pins and recorded data for roughly five seconds. There was a lot of background noise caused by the building power and high frequency noise generated by recording electronics. Still, we were able to obtain a recording of the spontaneous activity of a cockroach leg. The readings basically show the voltage difference of an action potential between the two insect pins inserted into the leg. In figure1 the max amplitude was 0.00006mV and only one action potential of that size was recorded during our sample. Another noticeable action potential had a reading of 0.00004mV. This occurred 14 times within a timeframe of 2.1 seconds. This corresponds to a frequency of 6.67 Hz. I could identify a third action potential of another size. This one had an amplitude of 0.00005mV and it only occurred once. Overall, the cockroach leg’s spontaneous activity was not consistent in amplitude or...