The story is well known: a frog preparation, consisting of the lower body half with exposed nerves and a metal wire inserted across the vertebral canal, starts contracting vigorously when one of Galvani’s collaborators touches its crural nerves with a lancet, and a spark rises from a distant electric machine

This paper explores Galvani's groundbreaking experiments on animal electricity, which initiated vital discussions surrounding the relationship between electrical activity and muscular contractions. The objective of the study is to elucidate the experimental conditions under which Galvani demonstrated the existence of intrinsic electrical phenomena in living organisms. Utilizing a frog preparation, Galvani assessed various external electric sources and their capacity to induce contractions in isolated nerves. He documented the response to both artificial and atmospheric electricity, ultimately concluding that muscle fibers possess intrinsic electrical properties akin to those of a Leyden jar. His findings suggest that electrical stimulation could elicit muscle contractions without reliance on external atmospheric conditions. Through meticulous observations, he established that the quality of connections between nerves and conductors determined the effectiveness of induced contractions. This pivotal research laid the foundations for our understanding of animal electricity, revealing that the flow of internal electricity is crucial for muscular activity. The relevance of voltage-dependent facilitation is also highlighted, as subsequent studies point to significant roles for L-type Ca2+ channels in mediating catecholamine release during physiological responses. Galvani's contributions fundamentally transformed the field of electrophysiology, bridging the gap between biology and electricity.