Neocortical cell classes are flexible entities

In studies on preparations in which spontaneous activity is significantly reduced or negligible, the properties of different cortical neuronal classes seem to be inflexible. But intracellular studies in behaving animals have led to the conclusion that firing patterns can be transformed from one type into another by slight changes in the membrane potential during shifts in the state of vigilance. Also, the incidence of various neuronal types in wakeful animals is different from that reported in vitro or under anaesthesia. The variation in firing pattern and incidence of cellular classes might shed light on the role of the different neuronal types across the waking - sleep cycle and related oscillations, during synaptic plasticity and consciousness, and during the development of paroxysmal states.