There was substantial debate on whether the transmission of information between neurons was chemical or electrical in the first decades of the twentieth century, but chemical synaptic transmission was seen as the only answer after Otto Loewi's demonstration of chemical communication between neurons and heart muscle.
Nas primeiras décadas do século XX houbo un substancial debate sobre se a transmisión da información entre neuronas era química ou eléctrica, pero a transmisión sináptica química foi considerada a única resposta válida despois da demostración de Otto Loewi da comunicación química entre as neuronas e o músculo cardíaco.