Having an electrode gain access to the intracellular space is the ultimate way to record activity within the impaled neuron.

There are two general techniques to conducting intracellular recordings; high impedence sharp electrodes or patch clamp. Here is a brief history of intracellular recordings from my thesis.

In both recording paradigms the tip of the electrode cannot contain bubbles. For this reason I use filamented borosilicate capillaries Click here for more information on electrodes. The difference between these two recording techniques is the size of the electrode tip.

"Sharp" electrodes are just that, very fine, recording is conducted by priking the neuron. Advantage: very little pertubation of the internal cellular space. Disadvatage: ineffective voltage-clamp.

"Patch-clamp" electrodes are larger then sharp electrodes. A patch electrode is placed on the membrane of the neurons and tight seal is made between the electrode and cell membrane. The membrane underneath the electrode is ruptured, either by the application of a a small amount of suction or brief current pulse. Advantage: good voltage-clamp. Disadvantage: the internal cellular space is continuous with the solution in the electode.

With the unimpeded access to the intracellular space great intracellular staining can accomplished.