Field potential shape in hippocampal slices

Dear MEA users,

In my short experience with MEAs I noticed that it is not easy to record a clean fEPSP. The electrodes located in different parts of stratum radiatum usually all produce nice population spikes with a clear positive deflection. Interestingly, clean EPSPs are seldom seen in MEA literature. This is in contrast to conventional recordings using glass/metal electrodes, where it is much easier to obtain fEPSPs uncontaminated with spikes. Could anyone suggest a plausible explanation?

I have got another queston concerning pre-coating of MEAs with nitrocellulose. How does one get rid of the old coating quickly if it is necessary to change the slice?

Many thanks for any info on these questions

Max

Dear Max

>I have got another queston concerning pre-coating of MEAs
>with nitrocellulose. How does one get rid of the old coating
>quickly if it is necessary to change the slice?

1. Directly after usage, biological material is rinsed off under running water and the MEA is cleaned with pH-neutral cleaning agents or enzymatically if necessary.
2. Methanol is applied for 15 to 30 min to dissolve the cellulose nitrate.
3. The MEA is then rinsed with distilled water.

It is very important that you clean MEAs that have been coated with nitrocellulose and remove all biological material first before removing the coating. If you applied methanol on an uncleaned MEA, you would rather fix the cell debris on the MEA than actually remove the
coating.

I am not sure whether you already have a revised version of the MEA User Manual, which provides some recommendations on storage, cleaning, coating and such stuff. Please contact me directly if you need one and I will be happy to send you a PDF.

leisgen@multichannelsystems.com

Please ask if you need more information.

Best regards, Christine (MCS)

Dear Christine,

Thank you for the up-dated manual! Could you be more specific about pH-neutral cleaning agents? Would Triton-100 suit this purpose?
Has anyone tried treatment with proteases to clean MEAs by chance?

Thank you!

Max

I am not sure about the properties of Triton-100, but what I mean with a ph-neutral cleaning solution is a cheap and basic dish liquid or similar. It is only important that it is ph-neutral. So I would recommend to check this with a pH paper.