ANATOMICAL STRUCTURE ALONE CANNOT PREDICT FUNCTION

The central hypothesis of Braitenberg et al.'s target article - that t idal waves of parallel fiber excitation precisely activate Purkinje ce ll spiking - is hard to reconcile with recent neurophysiological and m odeling data. The assumed pattern of mossy fiber input seems unrealist ic, inhibition is likely to interfere with the proposed excitatory res ponses, and moreover, computer simulations show that the Purkinje cell is a poor coincidence detector.