The invention disclosed herein describes a novel therapeutic target for motoneuron diseases (altered dynamics of microtubules in neurons) methods for measuring the state of activity of this therapeutic target in subjects with established, incipient, or potential motoneuron disease the discovery of drug agents that modulate neuronal microtubule dynamics in living subjects with motoneuron diseases the discovery that administration of such agents, alone or in combinations, can improve MT-mediated transport of "cargo" molecules along and through axons the discovery that such modulation of altered microtubule dynamics and improvement in MT-transport of molecules along axons can provide marked neuroprotective therapy for living subjects with motoneuron diseases, including delay in symptoms and prolongation of survival and the discovery that monitoring of neuronal microtubule dynamics in response to therapeutic interventions in subjects with motoneuron diseases,, allows diagnostic monitoring, to optimize therapeutic regimens and treatment strategies in individual subjects or in drug trials.
