Growth cone dynamics and activity-dependent processes in neuronal network development
Van Pelt, J., Van Ooyen, A., and Corner, M. A. (1996). In: Mize, R. R., and Erzurumlu, R. S., eds. Neural Development and Plasticity, Progress in Brain Research 108. Amsterdam: Elsevier, pp. 333-346. [Full text: PDF]
Neuromorphogenesis and network formation proceed via the dynamic behavior of growth cones which mediate neurite elongation, retraction, redirection and synapse formation. Mature neurons have attained their morphological characteristics as result of this dynamic process. For syudying the determinants of neuronal shape it is therefore crucial to understand how shape characteristics emerge from properties of this dynamic process. Among the many processes involved in growth cone dynamics are the exploratory interactions of filopodia with the local environment, receptor mediated transmembrane signalling to cytoplasmic regulatory systems and the formation of the cytoskeleton in the elongating neurite, comprising the polymerization of tubulin into microtubules.
This chapter focuses on the emergence of shape characteristics in dendritic branching patterns, and on the impact of activity-dependent processes in neurite outgrowth and network formation. The role of spontaneous activity in the formation of cultured neuronal networks is emphasized. Mathematical models are shown to be crucial tools for studying these subjects by making it possible to examine rigorously hypothesized mechanisms at the the growth cone level for their consequences on emergent neuronal morphological and network properties. This paper aims to illustrate the fruitfulness of such an integrated theoretical and empirical approach. Finally, it is emphasized how activity-dependent mechanisms, serving primarily a homeostatic goal, underlie many emergent structural and functional neural network properties.