KCl gives you a very short lived activation, then the neurons lose their ionic gradient.

Notes:

1. Solution switch at the time of arrow.
2. Red line with question mark shows time where KCl enhanced activity is occurring but note the progressive depolarisation, neuron is losing its ionic gradient.
3. The perfusion system was a standard peristaltic pump with a 2 mL/min flow – the effect of solution exchange is not immediate.
4. Drugs added to standard ACSF
5. Using gabazine* or TTX instead can modulate activity for longer term tests. * Assuming there are interneurons in your culture.

Images adapted from Marquez-Lopez 2022

See Markez-Lopez et al 2023 where we tested activity dependent tau secretion using gabazine and TTX as modulators of neuronal activity.