Stimulation of cerebellum protects hippocampal neurons from global ischemia

We investigated whether electrical stimulation of the cerebellar fastigial nucleus (FN) can protect pyramidal neurons of the CA1 zone of dorsal hippocampus from delayed neuronal death caused by global ischemia. Stimulation of the FN for 1 h prior to transient 4-vessel occlusion in anesthetized rats salvaged 57% (p < 0.01) of pyramidal neurons from degeneration. This effect could be preconditioned. Sham simulation of FN or stimulation of the rostral ventrolateral medulla (RVL) were without effect (p > 0.5). Excitation of intrinsic neuronal pathways represented in FN can protect central neurons from global as well as focal ischemic degeneration. The brain contains systems designed to protect it from ischemia by mechanisms of central neurogenic neuroprotection acting independently of actions on cerebral blood flow.