Precise coordination of electrical discharge at the moment of freezing
This is where high-pressure freezing comes into play. It allows for the near-instantaneous immobilization of cells. By varying the time intervals between stimulation and freezing, membrane trafficking within synaptic terminals can be captured following the induction of an action potential. The Leica high pressure freezer, EM ICE, with electrical stimulation offers millisecond precision. To study neural circuits, it offers the precise coordination of electrical discharge at the moment of freezing. This advance in technology gives neurobiology the most reliable tool for capturing and imaging action potential and membrane trafficking events.
A new approach allows scientists to capture and image visualize highly dynamic processes or the structural changes of samples at a nanometer resolution and with millisecond precision. Dissecting the processes step-by-step makes it e.g. easier to follow the ultrafast recycling of synaptic vesicles at nerve terminals in detail. This phenomenon is key to understanding the pathogenesis of a number of neurological disorders. Learn about the basic functioning of the method in the animated video.
Leica Microsystems offers in cooperation with BiteSize Bio the webinar "Revealing Cellular Dynamics with Millisecond Precision". Learn how to turn Electron Micrographs in Motion Pictures of Neural Communication. The Webinar has been recorded on March 29th 2017. Speakers are Dr. Shigeki Watanabe, Johns Hopkins School of Medicine and Dr. Frédéric Leroux, Leica Microsystems.
Or why electrical stimulation and high-pressure freezing can be the way to visualize synaptic function.
It takes one-thousand of a second for a membrane to polarize and initiate an impulse of excitation. The ionic mechanism that governs this process is what makes life ossible. It is what maintains all vital process and help us crate memories, it is in any active cells of the heart and the brain, it is a bioelectric potential. But what really makes this process remarkable is that bioelectricity propagates with an incredible speed, faster than the speed of light. Capturing and dissecting such dynamic processes is everything but trivial.
Dr. Shigeki Watanabe, Department of Cell Biology, from Johns Hopkins University Baltimore, wrote a report
Watch the video about probing fast cellular events. It informs about how to use stimulation in combination with high pressure freezing to dissect synaptic vesicles endocytosis. Speaker: Erik M. Jorgensen, University of Utah.
In addition to the video at the left a video by Jove demonstrates a procedure how to capture membrane dynamics by electron microscopy following induction of neuronal activity using optogenetics and freezing cells at defined timepoints after stimulation. This method can help to answer key question in Neuroscience and cell biology about the mechanisms of synaptic vesicle recycling. Watch the Jove video.