Figure 1.

Schematic depicting the astroglial and microglial responses to a variety of invasive experimental therapeutic approaches being trialed for neurodegenerative disorders (1–3). (4) Potential cell interactions that may further influence the outcome of the therapeutic intervention, or, that could be used to potentiate the effects of these therapies. For example the astrocytic response may lead to the release of trophic factors, the modulation of local blow flow as well as the activation of axonal circuits via tripartite synapses. The microglial response may produce both neuroprotective and neurotoxic products, all of which may impact not only on local neurons but also on local vasculature to influence the efficacy of the delivered therapeutic agent. Note: p-zone refers to areas of the graft expressing markers for striatal cells.