structures of brain cells change when humans and animals learn and form memories. Specifically, small protrusions
called dendritic spines, which receive signals from other neurons, can
grow and change shape indefinitely in response to stimulation.
Scientists at Max Planck Florida Institute for Neuroscience (MPFI) have
observed this process, known as long-term structural plasticity, in
individual spines, but doing so requires substantial time and effort.
‘The newly developed software that automates brain imaging helps increase productivity. The ability to stimulate and image multiple spines in parallel greatly decreases the cost of running these experiments.’
new technique, developed by MPFI researchers, automates the process to
make observing and quantifying this growth far more efficient. The
open-source method is available to any scientist hoping to image
plasticity as it happens in dendritic spines using Scanimage. The work
was published in January 2016 in the Public Library of Science journal, PLOS ONE
Scientists working in Ryohei Yasuda's laboratory at MPFI are working
to understand how proteins facilitate the plasticity of dendritic
spines, the biological basis of learning and memory.
They use two-photon
microscopy, an advanced technique for live-cell imaging, and glutamate
uncaging, a technique that can induce plasticity in individual spines of
interest using light. This is a meticulous process, wherein a scientist
must continually focus the microscope on a single dendritic spine over
an extended period, often an hour or longer.
Michael Smirnov, Post-doctoral researcher at MPFI, developed a software that allows the
computer to automatically track, image, and stimulate up to five
dendritic spines at a time. "We can collect the data and figure out the
proteins responsible much quicker with this [program] because we can run
much more robust experiments," said Smirnov.
In addition to increasing
productivity, the ability to stimulate and image multiple spines in
parallel greatly decreases the cost of running these experiments.
The software is a MATLAB-based module built for Scanimage, a program
already commonly used in life science laboratories. It includes an
electrically tunable lens in combination with a drift correction
algorithm. These aspects allow the program to identify and correct for
sample movement to ensure that the microscope is consistently focused on
the spines of interest throughout the duration of the experiment. The
interface provides an inexpensive method for automating experiments that
observe up to five dendritic spines at a time, as opposed to a single
spine using existing methods.
In contrast to previous open-sourced focusing programs, this one
implements a highly capable and customizable focus and drift correction
system to ensure that it can be used for a variety of biological
applications. "The paper explains further modifications to make the
process automated," said Smirnov. "It shares the open source code, so
essentially, other people from other institutes can easily pick this up
and use it for themselves."