John Nicholls is known for his analysis of regeneration in the nervous system after injury. For his PhD in Bernard Katz’s lab, he studied denervated skeletal muscle and sensory transduction. Later, John and Stephen Kuffler studied interactions of glial cells with neurons and demonstrated that extracellular potassium acts as a signal within the nervous system. Subsequent work focused on the properties and functions of individual, identified neurons in the leech central nervous system, particularly on the way in which they regrow to restore function after injury.
He and his colleagues showed that repair of the injured spinal cord also occurs in immature mammals — a property that is lost with age. John’s recent work deals with how the unfailing rhythm of respiration is produced by neurons in the brain stem of foetal mice, by the use of optical imaging, a technique that permits researchers to record the activity from hundreds of cells at once. He is the author of From Neuron to Brain and a memoir, Pioneers of Neurobiology: My Brilliant Eccentric Heroes (2015).