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This commit is contained in:
Jan Grewe
2020-01-20 15:55:31 +01:00
parent d7cda9567f
commit a46fa34b52
4 changed files with 31 additions and 33 deletions
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projects/project_photoreceptor/photoreceptor.tex
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@@ -12,20 +12,16 @@
%%%%%%%%%%%%%% Questions %%%%%%%%%%%%%%%%%%%%%%%%%
\section*{Light responses of an insect photoreceptor.}
In this project you will analyse data from intracellular recordings of
In this project you will analyze data from intracellular recordings of
a fly R\,1--6 photoreceptor. These cells show graded membrane
potential changes in response to a light stimulus. The membrane
potential of the photoreceptor was recorded while the cell was
stimulated with a light stimulus. Intracellular recordings often
suffer from drifts in the resting potential. This leads to a large
variability in the responses which is technical and not a cellular
property. To compensate for such drifts trials are aligned to the
resting potential before stimulus onset.
stimulated with a light stimulus.
\begin{questions}
\question{} The accompanying dataset (photoreceptor\_data.zip)
contains seven mat files. Each of these holds the data from one
stimulus intensity. In each file are three variables. (i)
stimulus intensity and contains therr variables. (i)
\textit{voltage} a matrix with the recorded membrane potential from
10 consecutive trials, (ii) \textit{time} a matrix with the
time-axis for each trial, and (iii) \textit{trace\_meta} a structure
@@ -37,12 +33,20 @@ resting potential before stimulus onset.
\begin{parts}
\part Create a plot of the raw data. For each light intensity plot
the average response as a function of time. This plot should also
depict the across-trial variability in an appropriate way.
the individual responses as a function of time.
\part You will notice that the responses have three main parts, a
pre-stimulus phase, the phase in which the light was on, and
finally a post-stimulus phase. Create an characteristic curve that
\part Intracellular recordings often suffer from drifts in the resting
potential. This leads to a large variability in the responses which is technical and not a cellular
property. To compensate for such drifts trials are aligned to the
resting potential before stimulus onset.
Replot the data but with the compensation for the drifts.
\part Instead of plotting individual responses plot the average response.
This plot should also depict the across-trial variability in an appropriate way.
\part You will notice that the responses have three main parts, (i) a
pre-stimulus phase, (ii) the phase in which the light was on, and (iii)
a post-stimulus phase. Create an characteristic curve that
plots the response strength as a function of the stimulus
intensity for the ``onset'' and the ``steady state''
phases of the light response.