Fine Structure of the Large Neurons and Their Processes: Dendritic Thorns and Their Synapses

Abstract

In the previous chapters, the location and gross morphology of the cerebellar nuclei were described, along with an estimation of cell numbers; the size, shapes, and dendritic and axonal characteristics of the neurons and their specific distributions within the segments of the dentate nucleus have also been detailed. On the basis of this information, cytological studies at a more refined level can be undertaken. Single cells can be examined at the fine structural level and their identifying features detailed. More important, it will now be possible to scrutinize the nature and quantity of the synaptic connections with other nuclear neurons and with axons of cortical and extracerebellar origins. For example, the large dentate neuron belongs to a prominent category defined by its size and the disposition of its axons. As its name implies, it is large and its axon undeniably projects out of the cerebellum via the superior cerebellar peduncle to red nucleus, thalamus, and other centers in the brain stem.