IAC-USNC Methods in Neuroscience- in vitro slice preparation

Visualizing individual neuronal cell bodies
Click HERE for a short video(7 MB) showing what it looks like to focus up and down through the slice and seeing the electrode going through the slice and contacting the selected neuron.

A hippocampal slice as seen using differential interference contrast (DIC) and near-infrared illumination. A row of large cell bodies can be seen along the diagonal from lower left to upper right. The target cell is in the center of the field of view.

The recording pipette (blue arrow) is approaching the target cell Joe has selected. Positive pressure keeps the pipette tip from coming in contact with debris.	Here the website designer has colored the pipette pink and the cell orange, just for clarity.
The pipette has contacted the cell and the positive pressure is released. In the video, you can see the pipette pushing on the cell and deflecting it slightly.	The oscilloscope shows that a tight seal has been made on the cell. The procedures used to make a patch clamp recording are much the same as those described in the web pages explaining the "whole cell patch clamp" technique.

The same images can been seen on the monitor by people observing the experiment.

Here the cell has been colored orange and the pipette pink.

Lowering the pipette toward the slice Click HERE for a 15 sec video (2.3 MB) of what one cycle of this process looks like in real-time.
For beginners it can sometimes be a challenge to find the pipette under the microscope and to lower the pipette without crashing it into the slice.

First the pipette tip is brought into focus.	Then you focus lower through the bath solution; the pipette is temporarily out of focus.	Then you slowly lower the pipette...	until it comes into the current focal plane. You repeat this procedure until the pipette is positioned slightly above the slice.