s from WT and Sgce KO mouse brains and analyze the levels of the interacting proteins by Western blot with antibodies against the identified proteins. Specific Aim 3: To analyze the effect of loss of ?-SG on the synaptic transmission and plasticity, we will determine input output relationship, paired pulse ratio, and long-term potentiation of hippocampal CA1 Schaffer collateral pathway. The successful completion of the above Specific Aims will produce a list of candidate synaptic proteins that interact with ?-SG and the effects of loss of ?-SG on their expression levels and synaptic transmission. The results should help us to determine the function of ?-SG in vivo and how the mutation of Sgce causes M-D. The results should significantly increase our understanding of the pathophysiology of M-D, which can ultimately aid the development of therapeutic treatments for M-D patients and other dystonia and myoclonus patients.

The development of movement depends on the maturation of the spinal cord motor circuits. Embryonic motor output is characterized first by spontaneous activity resulting in fetal jerk movements that later become more rhythmic and show limb alternations. In newborns motor development then undergoes a period of reflex and postural maturation leading into coordinated weigh-bearing locomotion. All these changes occur as a consequence of different maturation phases of the spinal synaptic networks and more specifically of local interneurons that ultimately control motor neuron firing patterns and motor output. Our long term objective is to understand the development of these local spinal circuits. Advances in this field were hampered in the past by the diversity and complexity of spinal interneurons. Fortunately, the recent development of mouse models expressing genetically-encoded reporters to identify interneuronal lineages now permits their study through development and allowed new understanding of the principles that govern spinal interneuron development. Our work has been focusing on one lineage of e