OPA1 and toxic encephalopathy: DL-3-n-Butylphthalide Protects Against PrP&lt;sup&gt;106&lt;/sup&gt; &lt;sup&gt;-126&lt;/sup&gt;-Induced Neurotoxicity Through NRF2 Signaling and OPA1/DRP1-Mediated Mitochondrial Dynamics.