ESTROGEN PROTECTS PRIMARY CORTICAL-NEURONS FROM GLUTAMATE TOXICITY

The gonadal steroid estrogen has been shown to affect neuronal growth, differentiation and survival We examined the ability of estrogen to p rotect primary cortical neurons from toxicity induced by the excitator y neurotransmitter glutamate. In these experiments, a 24-h pretreatmen t with 15 and 50 nM 17 beta-estradiol significantly reduced cellular l actate dehydrogenase (LDH) release from primary cortical neurons, indi cating that neurons treated with 17 beta-estradiol were protected from a toxic glutamate exposure. Pretreatment with related steroids such a s progesterone, dihydrotestosterone, dexamethasone or cholesterol did not significantly decrease LDH release. The anti-estrogen tamoxifen bl ocked the protective effects of 17 beta-estradiol suggesting that a cl assical steroid hormone receptor may be involved in the mechanism subs erving estrogen neuroprotection during glutamate toxicity.