Oestrogens and Progestagens: Synthesis and Action in the Brain

Abstract

When steroids, such as pregnenolone, progesterone and oestrogen, are synthesised de novo in neural tissues, they are more specifically referred to as neurosteroids. These neurosteroids bind specific receptors to promote essential brain functions. Pregnenolone supports cognition and protects mouse hippocampal cells against glutamate and amyloid peptide-induced cell death. Progesterone promotes myelination, spinogenesis, synaptogenesis, neuronal survival and dendritic growth. Allopregnanolone increases hippocampal neurogenesis, neuronal survival and cognitive functions. Oestrogens, such as oestradiol, regulate synaptic plasticity, reproductive behaviour, aggressive behaviour and learning. In addition, neurosteroids are neuroprotective in animal models of Alzheimer's disease, Parkinson's disease, brain injury and ageing. Using in situ hybridisation and/or immunohistochemistry, steroidogenic enzymes, including cytochrome P450 side-chain cleavage, 3b-hydroxysteroid dehydrogenase/D5-D4 isomerase, cytochrome P450arom, steroid 5a-reductase and 3a-hydroxysteroid dehydrogenase, have been detected in numerous brain regions, including the hippocampus, hypothalamus and cerebral cortex. In the present review, we summarise some of the studies related to the synthesis and function of oestrogens and progestagens in the central nervous system.

Puberty and structural brain development in humans

“…However, basic research is also needed to better understand how other factors may influence the bioavailability of peripheral hormone levels, such as individual differences in aromatase activity (which converts testosterone to estradiol)(Lephart, Simpson et al. 1992), de novo steroid synthesis in brain tissues (Pelletier 2010, Rossetti, Cambiasso et al 2016), and variation in the composition and neural location of sex steroid receptors as a function of pubertal development (Kashon and Sisk 1994). …”

Protective Cellular Mechanism of Estrogen Against Kidney Stone Formation: A Proteomics Approach and Functional Validation

“…This hormone plays essential roles in regulation of female characteristics and is also involved in development and homeostasis of several tissues. In addition to the reproductive system, estrogen also affects brain, kidney, heart, and so on. Several lines of evidence have reported that estrogen can regulate protein expression, oxidative stress, and ATP synthesis .…”

The aminoestrogen prolame increases recognition memory and hippocampal neuronal spine density in aged mice

“…Estrogens are involved in maintaining brain function (Galea, Frick, Hampson, Sohrabji, & Choleris, ; Rossetti, Cambiasso, Holschbach, & Cabrera, ). These hormones interact with different receptors, including alpha and beta estrogen, which are present in the brain (Almey, Milner, & Brake, ; Mikosha, Kovzun, & Tronko, ).…”