Crayfish Lab Report
November 9, 2012
Dr. Marvin
Results:
Figure 1. Firing Rate of Tonic Receptor in Response to Stretch. The correlation between Firing Rate and Stretch of the slow adapting crayfish receptor for four different sets of data is represented in this figure. The recordings are taken at stretches of 2, 4, 6, 8, and 10 mm of the crayfish tail. The best fit lines for the different sets of data are as follows: Ali and Emily- Linear best fit line, Dave and Laura- Exponential best fit line, Jimmy and Amina-Exponential best fit line, Tala and Jen-Linear best fit line).
Figure 2. Class Average for Firing Rate of Tonic Receptor in Response to Stretch. The firing rate of the slow-adapting receptor neuron in response to stimulus, which in this experiment is the stretching of the Crayfish tail at 2, 4, 6, 8 and 10 mm.
Figure 3. Rate of Adaptation of Tonic Receptor held at Constant Length (6mm). The best fit line for the rate of adaptation of the Tonic receptor is Logarithmic. At a constant stimulus, the initial firing rat drops and levels off at a constant firing rate representing the presence of a stimulus.
R2 Values for Linear, Exponential and Logarithmic Lines for each Data Set | Curve Type | R^2 | Tala, Jen | Linear | 0.982 | | Exponential | 0.982 | | Logarithmic | 0.982 | Dave, Laura | Linear | 0.982 | | Exponential | 0.982 | | Logarithmic | 0.746 | Jimmy, Amina | Linear | 0.950 | | Exponential | 0.976 | | Logarithmic | 0.824 | Ali, Emily | Linear | 0.988 | | Exponential | 0.934 | | Logarithmic | 0.965 | Class Average | Linear | 0.995 | | Exponential | 0.966 | | Logarithmic | 0.920 |
Discussion:
3. Frequency vs Stretch
a) In our classroom experiment, after dissecting and preparing our crayfish tail, we sucked up a MRO receptor neuron with our electrode to record firing of the nerve as we adjusted the length of the crayfish tail using a string attached to both the
References: Nakajima, Shigehiro. "Adaptation in Stretch Receptor Neurons of Crayfish." Science 1 ( 1964): n. pag. Delcomyn, Fred. "Encoding Stimulus Strength." (n.d.): n. pag. Krnjevic, K., and N. M. Van Gelder. "Tension Changes in Crayfish Stretch Receptors."J. Physiology (1961): n. pag.