Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2004.Includes bibliographical references (leaves 112-126).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.This thesis takes as its subject three model systems which exhibit interesting properties in the developing nervous system. The first study details the developmental properties of dendritic spines, the principle sites of excitatory synaptic contacts, during a period of synaptogenesis in the developing mouse cortex. The second study extends these findings and examines the properties of dendritic spines during a period of heightened visual cortical plasticity and describes how manipulations of visual input alter these dendritic structures. The third and final study examines the distribution of glutamate receptors, which are key components of excitatory synaptic contacts, during a period of stereotyped anatomical plasticity in the developing ferret lateral geniculate nucleus. Each of these studies focus specifically on the interactions between neuronal structure and function, principally at the level of synaptic contacts. The conclusions of this thesis are that structure and function are intimately related and that altering one has important consequences for the other.by Serkan Oray.Ph.D.