Technically, you're correct. Brain signals are of a electrochemical nature, which means you have chemical signals such as dopamine, serotonin, glutamate etc. at the synaptic terminals which then cause the release of ions such as calcium, sodium, potassium and chloride which are found in different concentrations in the extracellular space and intracellular environment. The passage and exchange of these ions then creates a net "charge" which makes up the "electro" component of the signal. From that point, the signal is subjected to modulation and amplification by intercommunication with other proteins. Signal transduction is incredibly complex, but is great to see, learn and be able to control the exact way by which a cell differentiates, grows, proliferates and dies. Once you know this, you can control what the cell does by designing drugs that block a certain signal or mimics the effect of a chemical produced in the body (like DMT).