Abstract
Circuit dynamics are an outcome of the constant interplay between the intrinsic properties of neurons and the strengths of the synaptic connections among them. Examples from the small networks that generate the rhythms of the crustacean stomatogastric ganglion are used to illustrate general features of the different time scales over which both synaptic and intrinsic properties are altered by circuit activity and neuromodulation. These demonstrate that neither intrinsic membrane properties nor synaptic strengths should be considered fixed parameters; rather, they are dynamic variables with time scales that range from milliseconds to days. NEUROSCIENTIST 3:295–302, 1997