Most of the chapters in this section could have been included under the heading of ‘motor control’, but we have chosen the present heading because we wished to include some areas which, although they might normally be considered outside motor control, may nevertheless be particularly relevant in a pathological situation. Thus we start with Crill's review of channels in neocortical neurones, knowledge of which is not only fundamental to an understanding of upper motor neurone physiology, but is also relevant to many other types of neurone. Similarly, the hippocampus may not normally be considered part of motor systems, yet the way in which it displays seizure behaviour (see chapter by Jefferys) may well be a model for disorders of other cortices. Accompanying this, the chapter from Andersen contains important data vital for any experimenter wishing to extrapolate from in vivo experiments in this field to equivalent results in behaving animals.

The chapters by Taylor & Durbaba, Aminoff & Goodin and Prochazka et al. cover areas more normally considered under motor control. That by Taylor & Durbaba on the physiological significance of fusimotor drives is particularly relevant to this volume because it draws comparisons between the control of limb muscles and the control of respiratory muscles. This latter is an area covered in a further nine chapters in this section. Respiratory movements are some of the most automatic, yet the respiratory muscles are used for one of the most voluntary actions, speech, as well as many other more or less automatic actions (see chapter by Grélot et al.).