Postnatal development of synaptic inputs to rat masseter motoneurons

We examined postnatal changes in rat masseter motoneuron morphology and the density of synaptic inputs to masseter motoneurons using retrograde labeling combined with synaptophysin immunohistochemistry. The cross-sectional area and perimeter of masseter motoneurons increased through P21 whereas synaptic input density increased throughout the time frame sampled. Data suggest that changes in masseter motoneuron morphology and the density of its synaptic input contribute to the maturation of mastication behavior.