MODELING MOTONEURON FIRING PROPERTIES - DEPENDENCY ON SIZE AND CALCIUM DYNAMICS

The origin of functional differences between motoneurons of varying si ze was investigated by employing a one-compartmental motoneuron model containing a slow K+ conductance dependent on the intracellular calciu m concentration. The size of the cell was included as an explicit para meter. Simulations show that motoneurons of varying size cannot be reg arded as simple 'scaled' versions of each other. Rather, they are expe cted to have intrinsic properties that vary with cell size. These intr insic properties refer to the membrane conductances per unit area and the dynamics of the intracellular calcium concentration.