Galvani's spark

Galvani's chronicles the gradual understanding of the nerve impulse which is the basis of all thoughts, sensations and actions. The story begins with Luigi Galvani's chance observation of a spark from a friction machine causing a frog's leg to twitch from across the room. The accurate recording and the understanding of the properties of the nerve fiber membrane that makes the impulse possible became the objectives of neuroscientists for over 200 years. The author, Alan J. McComas finely interweaves the stories, the challenges, and the controversies of the most prominent figures in neuroscience, from the histological descriptions of nerve cells by Cajal to the discovery of a three-dimensional structure of ion channels in cell membranes by MacKinnon. Along the way he details the first recordings of the impulse with a cathode ray oscilloscope by Gasser and Erlanger, Adrian's discovery that stimulus intensity is coded by the frequency of nerve impulses, and Hodgkin and Huxley's brilliant voltage clamp experiments, amongst many others.The recognition by Galvani that muscles and nerves have an electrical component triggered the field of neurophysiology and in turn has produced some of the greatest discoveries in neuroscience.