Poststroke neuronal rescue and synaptogenesis mediated in vivo by protein kinase C in adult brains

Global cerebral ischemia/hypoxia, as can occur during human stroke, damages brain neural networks and synaptic functions. The recently demonstrated protein kinase C (PKC) activation-induced synaptogenesis in rat hippocampus suggested the potential of PKC-mediated antiapoptosis and synaptogenesis during conditions of neurodegeneration. Consequently, we examined the effects of chronic bryostatin-1, a PKC activator, on the cerebral ischemia/hypoxia-induced impairment of synapses and neurotrophic activity in the hippocampal CA1 area and on hippocampus-dependent spatial learning and memory. Postischemic/hypoxic bryostatin-1 treatment effectively rescued ischemia-induced deficits in synaptogenesis, neurotrophic activity, and spatial learning and memory. These results highlight a neuroprotective signaling pathway, as well as a therapeutic strategy with an extended time window for reducing brain damage due to stroke by activating particular PKC isozymes.