Abstract

Estradiol plays a critical role in sexual maturation and receptivity. These effects are well characterized: primarily mediated through intracellular estrogen receptors, estradiol initiates changes in gene expression, leading to alterations in cell excitability. But estradiol also influences neuronal plasticity via rapid actions initiated at the plasma membrane. Many intracellular signaling pathways are modulated by estradiol via this unconventional method, influencing various brain functions such as learning and memory, sensorimotor control and nociception. Yet, the mechanism by which estradiol acts at the membrane remains unknown. Preliminary data suggest that estradiol, through interactions with a membrane localized receptor, activates both group I and group II metabotropic glutamate receptors, leading to alterations in several major signaling cascades. This previously undefined mechanism of estradiol action can theoretically account for the majority of unexplained actions of the steroid hormone. The central hypothesis of this proposal is that through activation of metabotropic glutamate receptors, estradiol has profound influences upon brain function.
Specific Aim 1 will characterize the effects of estradiol, through activation of metabotropic glutamate receptors, upon CREB and NFATc4, as these two transcription factors are essential regulators of many behaviors. Moreover, we will quantify mRNA expression for genes regulated by CREB and NFATc4 following estradiol administration.
Specific Aim 2 will delineate the mechanism by which estradiol activates metabotropic glutamate receptors. Experiments will detail estrogen receptor specificity, gender specific differences in estradiol sensitivity, and interactions between estrogen and glutamate receptors. In sum, this study will attempt to decipher a long standing mystery regarding the actions of estradiol upon the central nervous system. It will potentially provide a unifying theory detailing a principal mechanism by which estradiol can rapidly trigger changes in cell excitability and ultimately lead to a better understanding of how estradiol modulates brain function.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS041302-08
Application #
7536015
Study Section
Neuroendocrinology, Neuroimmunology, and Behavior Study Section (NNB)
Program Officer
Stewart, Randall R
Project Start
2001-07-02
Project End
2010-11-30
Budget Start
2008-12-01
Budget End
2009-11-30
Support Year
8
Fiscal Year
2009
Total Cost
$287,232
Indirect Cost

  Institution

Name
University of Minnesota Twin Cities
Department
Neurosciences
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455

  Publications

Luoma, Jessie I; Stern, Christopher M; Mermelstein, Paul G (2012) Progesterone inhibition of neuronal calcium signaling underlies aspects of progesterone-mediated neuroprotection. J Steroid Biochem Mol Biol 131:30-6
Mani, S K; Mermelstein, P G; Tetel, M J et al. (2012) Convergence of multiple mechanisms of steroid hormone action. Horm Metab Res 44:569-76
Meitzen, John; Mermelstein, Paul G (2011) Estrogen receptors stimulate brain region specific metabotropic glutamate receptors to rapidly initiate signal transduction pathways. J Chem Neuroanat 42:236-41
Meitzen, John; Pflepsen, Kelsey R; Stern, Christopher M et al. (2011) Measurements of neuron soma size and density in rat dorsal striatum, nucleus accumbens core and nucleus accumbens shell: differences between striatal region and brain hemisphere, but not sex. Neurosci Lett 487:177-81
Srivastava, Deepak P; Waters, Elizabeth M; Mermelstein, Paul G et al. (2011) Rapid estrogen signaling in the brain: implications for the fine-tuning of neuronal circuitry. J Neurosci 31:16056-63
Stern, Christopher M; Meitzen, John; Mermelstein, Paul G (2011) Corticotropin-releasing factor and urocortin I activate CREB through functionally selective Gýýýý signaling in hippocampal pyramidal neurons. Eur J Neurosci 34:671-81
Luoma, Jessie I; Kelley, Brooke G; Mermelstein, Paul G (2011) Progesterone inhibition of voltage-gated calcium channels is a potential neuroprotective mechanism against excitotoxicity. Steroids 76:845-55
Stern, Christopher M; Luoma, Jessie I; Meitzen, John et al. (2011) Corticotropin releasing factor-induced CREB activation in striatal neurons occurs via a novel Gýýýý signaling pathway. PLoS One 6:e18114
Stern, Christopher M (2011) Corticotropin-releasing factor in the hippocampus: eustress or distress? J Neurosci 31:1935-6
Kelley, Brooke G; Mermelstein, Paul G (2011) Progesterone blocks multiple routes of ion flux. Mol Cell Neurosci 48:137-41

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