Resistance of extraocular motoneuron terminals to effects of amyotrophic lateral sclerosis sera

In sporadic ALS (s-ALS), axon terminals contain increased intracellular cal cium. Passively transferred sera from patients with s-ALS increase intracel lular calcium in spinal motoneuron terminals in vivo and enhance spontaneou s transmitter release, a calcium-dependent process. In this study, passive transfer of s-ALS sera increased spontaneous release from spinal but not ex traocular motoneuron terminals, suggesting that the resistance to physiolog ic abnormalities induced by s-ALS sera in mice parallels the resistance of extraocular motoneurons to dysfunction and degeneration in ALS.