This image shows the confocal microscope used for electrophysiology experiments. The lasers are in black tubes in the back corner of the table. Micromanipulators are on the table next to the microscope in order to help me move the glass pipette tubes with fine precision. The large computer screen shows a picture of a Purkinje cell.
To do these experiments, I attach a small, glass tube that is filled with dye to the membrane of one neuron. After the tube is attached, the dye is free to flow from the tube into the neuron. Over a period of 30-40 minutes, the dye slowly fills all the tiny branches of dendrites. I provide some electrical pulses to the neuron to measure its activity. The dye provides us with a way to visualize the neuron’s electrical activity.
This images shows a brain slice (middle) incubating in a bath that has specified concentrations of ions and glucose. Above the brain slice, the microscope lens hovers. Two glass tubes called pipettes touch the brain slice to provide electrical stimulation and measure how the neuron responds to such stimulation. There are two other glass tubes for the bath solution to enter and exit, and there’s one grounding electrode (right) to complete the electrical circuit.
When the experiment is over and I have collected as much data as I can, I use the confocal microscope to take a series of photographs of the neuron on different planes, since it’s a three-dimensional structure. The microscope coordinates cues from different software and hardware to take the neuron’s portrait. After the stack of images (~40 images) from different planes is complete (15-30 minutes), I collapse the images into one picture that incorporates each layer and shows the entire neuron. Once I have this final picture, I apply different filters to the images to change the colors and texture.
This week, Richelle and I have been talking about how to print some of my pictures and then add extra materials to increase the texture in the images. I was looking for ways to portray the three dimensions of these neurons even when they’re printed in two dimensions. Richelle recommended mixing NovaPlex with acrylic paint to build up some layers, and I’m looking forward to trying it. In the past, I have collected images of neurons, but have never taken the next step to print the pictures and add to them. This will be an exciting adventure, and a new kind of experiment for me. Check back next Tuesday for updates and neurons!