NT-4 5 PROTECTS AGAINST ADRENALECTOMY-INDUCED APOPTOSIS OF RAT HIPPOCAMPAL GRANULE CELLS/

ADRENALECTOMY (ADX) in rats has been shown to induce apoptosis of hipp ocampal granule cells. We tested whether neurotrophins are able to pro tect hippocampal neurons in this neurodegeneration model. Acid fuchsin stain was used to identify pyknotic cells in ADX rats treated for 4 d ays with NT-3, NT-4-5 or cytochrome-C, as a control protein. Cytochrom e-C injections slightly decreased cell death on the ipsilateral side. NT-3 did not further promote this effect. Significantly less cell deat h was observed bilaterally in hippocampus treated with NT-4/5. TUNEL e nd labeling also confirmed the results. Our results demonstrated that NT-4/5, but not NT-3, promotes hippocampal neuron survival in adrenale ctomized rats. They further show that injections of a control solution can induce a local protective effect.