Allopregnanolone prevents memory impairment: Effect on mRNA expression and enzymatic activity of hippocampal 3-α hydroxysteroid oxide-reductase

Environmental enrichment attenuates the age-related decline in the mRNA expression of steroidogenic enzymes and reduces the methylation state of the steroid 5α-reductase type 1 gene in the rat hippocampus

“…Similarly, other studies have indicated that allopregnanolone can improve memory impairment and inhibit the symptoms of aging and neurodegenerative diseases. Escudero et al (2012) showed that treatment with estradiol benzoate alone or with progesterone in ovariectomized rats has amnesic effects and that allopregnanolone can reverse this effect, suggesting that the beneficial effects may include enhancement of the cognitive performance of the hippocampus. In patients with Alzheimer's disease, reduced allopregnanolone levels were observed in the prefrontal cortex (Marx et al, 2006).…”

“…Particularly, allopregnanolone promotes the proliferation of rodent neural progenitor cells and neuron survival (Wang et al, 2005), inhibits apoptosis in the late gestation fetal brain (Yawno et al, 2009), prevents memory impairment in rats (Escudero et al, 2012) and mice (Singh et al, 2012) and plays a key role in neurodegenerative diseases such as AD (Brinton, 2013;Irwin et al, 2011;Marx et al, 2006;Wang et al, 2008).…”

Understanding the role of steroids in typical and atypical brain development: Advantages of using a “brain in a dish” approach

“…One study reported prevention of age‐related memory loss in aged overiectomised rats following chronic administration of progesterone along with oestrogens . In certain cases, the progesterone metabolite allopregnanolone is involved in the recovery of age‐related cognitive deficits . Progesterone was also shown to enhance learning and memory, and to recover age‐related cognitive decline in aged wild‐type as well as progesterone receptor knockout mice .…”

“…84 In certain cases, the progesterone metabolite allopregnanolone is involved in the recovery of age-related cognitive deficits. 85 Progesterone was also shown to enhance learning and memory, and to recover age-related cognitive decline in aged wild-type as well as progesterone receptor knockout mice. 86 A possible cellular mechanism for the role of progesterone as a memory enhancer is its ability to provide neuroprotection against oxidative stress in the hippocampus, 87 by down-regulating pro-apoptotic markers and up-regulating anti-apoptotic markers.…”

Neurosteroids Involvement in the Epigenetic Control of Memory Formation and Storage

“…On the contrary, it was shown that young rats in proestrus and late pregnancy (i.e., reproductive conditions associated with higher cortical ALLO levels) exhibit better performance on the object recognition task than rats in dioestrous or early pregnancy conditions [81]. ALLO can also reverse the amnesic effects exerted by estradiol-benzoate alone or plus progesterone infused into the hippocampus of ovariectomized rats, probably through its direct modulation of hippocampal 3 α -HSD activity [82]. …”