Listening to "CCN Course 2020, Neuron 11: Ions". It tells about membrane potential, sodium and potassium pumps, allowing our neurons to work.
https://youtu.be/B0ziLwEhHfM?list=PLu02O8xRZn7xtNx03Rlq6xMRdYcQgEpar

…Have you ever thought that a neuron had evolved in a sea water?We carry a trace of an ancient ocean with us throughout our lives.

(Using a Silas Baisch image from Unsplash as a base for CLIP render.)