Gene therapy against neurological insults: sparing neurons versus sparing function

Increasing knowledge of neuron death mediators has led to gene therapy tech niques for neuroprotection. Overexpression of numerous genes enhances survi val after necrotic or neurodegenerative damage. Nonetheless, although encou raging, little is accomplished if a neuron is spared from death, but not fr om dysfunction. This article reviews neuroprotection experiments that inclu de some measure of function, and synthesizes basic principles relating to i ts maintenance. Variations in gene delivery systems, including virus-type a nd latency between damage onset and vector delivery, probably impact the th erapeutic outcome. Additionally, functional sparing might depend on factors related to insult severity, neuron type involved or the step in the death cascade that is targeted.