Synaptic Morphology in the Normal and Degenerating Nervous System

TLDR: It is emphasized that, in addition to transmission of impulses, the organization of neuroneuronal junctions is likely to include other important properties that cannot be ignored when the morphology of synaptic contacts is being considered.

Abstract: Publisher Summary This chapter focuses on the morphology of specialized neuronal contacts in general and of synaptic contacts in particular. The term “synapse” is used as a morphological term to describe specialized regions of contact between nerve cells and between nerve cells and effector organs. The structure of this specialized region is of crucial importance. Whereas epithelial cells in general show symmetrical contact regions such as the desmosomes and tight junctions the nervous system shows, in addition, asymmetrical contact regions, the “synaptic thickenings”. It is emphasized that, in addition to transmission of impulses, the organization of neuroneuronal junctions is likely to include other important properties. The interaction between neurons by which a nerve cell can maintain or even stimulate the growth and maturation of an innervated structure is likely to involve neuronal contacts, as is the ability of developing and regenerating axons to grow to and make contact with specific cell groups. Although relatively little is known about these aspects of neuroneuronal interaction they cannot be ignored when the morphology of synaptic contacts is being considered.