Dear Researchers,

We are working on hippocampal slice electrophysiological studies for assessing spike potentiating effects of cholinergic agonists like carbachol. For the evaluation of M1PAM like activity, M1PAMs' are highly hydrophobic in nature which requires a solubilizing agent to get dissolved in circulating ACSF perfusate.

With regular ACSF, we have no issues in view of spike potentiating effects upon carbachol addition. However, when we add even very low conc. of DMSO (less than 0.003% v/v), the spike rate is being drastically decreased.

Many of the earlier reports suggested to use DMSO even at higher conc., i.e. 0.1 - 1% or even up to 5% v/v for LTP/LTD studies.

At such higher conc.s', how can we expect the no change in electrical excitability properties of highly sensitive hippocampal slices?

Can we use another vehicle, like Pharmasolve to make test compounds dissolved in ACSF.

Please share your knowledge for selection of suitable/ good vehicle for assessing the ability of test compounds in inducing the LTP or LTD phenomenone in this Ex-vivo preparation.

Thanking you,

With Best Regards,

Grandhi V Ramalingayya