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scr movementinteractions 0

Jose Alonso (mac) edited this page May 1, 2020 · 2 revisions

Movement and interactions of macrophages

This file follows the development of the script scr_movementandinteractions.m. In this work, an analysis of the movement of the nuclei in the RED channel will be made, focusing on the interactions that happen before and after a couple of cells leave a clump.

This log will follow the development of the code. The overall flow of the work should:

  • Initialise: through initscript.m and by choosing a clump whichclump.
  • Choose the entries in tablenet that contain the tracks in whichclump. Get them into variable trackinfo.
  • Evaluate the tracks and choose an appropriate segment of the dataset that shows the cells before and after the clump.
  • Analyse the mean velocity before and after a certain amount of frames (10?, 100?, ...)
  • Analyse the direction before and after the clump (how many frames back should I consider the direction to be on? ...)
    • What to do with clumps that start aggregating with more and more cells?

Exploration of the data

Visualisation

Several qualitative tests have been carried out in order to determine the best course of action for the automated analysis. Function plotframeandpoint.m was developed to show a frame, with the overlapping and non-overlapping cells, while displaying a set of points of interest.

visualisation-1

In the figure, two frames of track 8 are shown; on the left, where the cell is on its own, and on the right some frames later when the cell is inside a clump. To represent whether the cell is part of a clump or single, different markers are used (.) for single and diamonds for clumped cells. Finally, different colours of the parula colourmap are used to display the different velocities at which the cell is moving in that particular frame (from blue to yellow).

The plotframeandpoint.m function has a mode in which no image is passed to it, which causes only the designated points to be shown on an already existing image. The following figure showcases this mode, arrows were added to highlight the direction of the cells during the time it was clumped and the times it was out of it. The sequence shown for track 8 is taken from timeframes 267:346 it shows the first frame in the sequence, and the progression of the cell as time passes. The velocity of the frame increases significantly after leaving the clump, then it appears to stop and then switches direction back up.

visualisation-2

Following the path set out before, from frames 306:406, the cell can be seen switching back to a different clump and then leaving it changing its original direction.

visualisation-3

Both pictures include interesting cases for the analysis for that particular cell. More cases have been looked for, but other problems arise when doing so. The visualisation of the entire track segment can be seen below.

visualisation-4

Velocity of nuclei inside and outside of clumps

A small test can be made to find out the velocity of nuclei within clumps in variable velclumps and outside of them using variable velsingles. This can be done through tablenet and clumptracktable in the following way:

velsingles = tablenet(clumptracktable.clumpcode==0,:).velocity;
velclumps = tablenet(clumptracktable.clumpcode~=0,:).velocity;
mean(velclumps) +/- (std) mean(velsingles) +/- (std)
1.6115 +/- (1.3981) 2.1671 +/- (1.6470)

A brief analysis was made to see if the difference between both states (clump and single) was significant for the mean velocity of the nuclei. The analysis used signrank and it shows that the hypothesis of velclumps - velsingles having zero median cannot be rejected.

Analysis of change of direction

In order to assess the changes in direction, a thorough review of the generated tracks by PhagoSight must be made, ensuring that any suddent change in direction detected was not caused by a track confusing nuclei when the cells were clumped and

The three datasets were analysed this time. The dataset normally used is dataset MACROS1, while the other two are labelled as MACROS2 and MACROS3. Below see visualisations of the macrophages moving with the finalLabel next to each track. The colours represent the velocity of the macrophage at that frame.

MACROS1 dataset visualisation-5-1

MACROS2 dataset visualisation-5-2

MACROS2 AN INTERESTING CASE is highlighted below, where two tracks interact various times and directions seem to change constantlty. visualisation-5-2-1

MACROS3 dataset visualisation-5-3

MACROS2: Example of change in direction

visualisation-6-1 visualisation-6-2

Measurement options for the angle

visualisation-6-1-1