Sex hormones affect neurotransmitters and shape the adult female brain during hormonal transition periods

Abstract

Sex hormones have been implicated in neurite outgrowth, synaptogenesis, dendritic branching, myelination and other important mechanisms of neural plasticity. Here we review the evidence from animal experiments and human studies reporting interactions between sex hormones and the dominant neurotransmitters, such as serotonin, dopamine, GABA and glutamate. We provide an overview of accumulating data during physiological and pathological conditions and discuss currently conceptualized theories on how sex hormones potentially trigger neuroplasticity changes through these four neurochemical systems. Many brain regions have been demonstrated to express high densities for estrogen- and progesterone receptors, such as the amygdala, the hypothalamus, and the hippocampus. As the hippocampus is of particular relevance in the context of mediating structural plasticity in the adult brain, we put particular emphasis on what evidence could be gathered thus far that links differences in behavior, neurochemical patterns and hippocampal structure to a changing hormonal environment. Finally, we discuss how physiologically occurring hormonal transition periods in humans can be used to model how changes in sex hormones influence functional connectivity, neurotransmission and brain structure in vivo.

Using positron emission tomography to investigate hormone-mediated neurochemical changes across the female lifespan: implications for depression

“…Progesterone, the other main ovarian hormone, also rises in level during puberty and remains relatively stable until perimenopause, when the level gradually but continuously decreases. For a more in-depth review of changes in ovarian hormones across the female lifespan, please see Barth, Villringer, and Sacher (2015).…”

“…Briefly, oestrogen facilitates glutamate transmission (Adams, Fink, Janssen, Shah, & Morrison, 2004; Gazzaley, Figure 1. Localization of oestrogen receptors, progesterone receptors, and monoaminergic pathways in the female brain (adapted with copyright permission granted from Barth et al, 2015). Co-expression of ovarian hormone receptors in the CNS alongside neurotransmitter localization.…”

“…The glutamatergic (pink), GABAergic (green), dopaminergic (blue), and serotonergic (yellow) pathways are displayed separately for clearer representation. For a detailed description of ovarian hormone receptor distribution in each pathway, please see Barth et al (2015). ( Weiland, McEwen, & Morrison, 1996;Smith & Woolley, 2004), which plays a significant role in synaptic plasticity, learning, and memory.…”

Introductory Chapter: A Multidisciplinary Look at Menopause

“…Sexual hormones, such as estradiol and progesterone, help regulate metabolic function and interact with a wide range of neurotransmiters, such as serotonin, dopamine, λ-aminobutyric acid, and glutamate, among others [3]. Lower concentrations of these hormones during menopause have been associated with the development of speciic diseases.…”

Evaluating the Role of Hormone Therapy in Postmenopausal Women with Alzheimer’s Disease

“…Progesterone has been shown to suppress the excitatory glutamate response (in a dose-dependent manner) protecting the neurons from glutamate excitotoxicity, while estrogen has the opposite effect by facilitating glutamate transmission [45]. Therefore, the interaction between sex hormones and classic neurotransmitters is a complex one in which estrogen and progesterone can have protective as well as toxic effects.…”