ChemInform Abstract: Neurosteroid Analogues. Part 5. Enantiomers of Neuroactive Steroids and Benz[e]indenes: Total Synthesis, Electrophysiological Effects on GABAA Receptor Function and Anesthetic Actions in Tadpoles.

ChemInform ◽  
2010 ◽  
Vol 29 (18) ◽  
pp. no-no
Author(s):  
Y. HU ◽  
L. L. WITTMER ◽  
M. KALKBRENNER ◽  
A. S. EVERS ◽  
C. F. ZORUMSKI ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Gabaa Receptor ◽  
Neuroactive Steroids ◽  
Receptor Function ◽  
Electrophysiological Effects

scholarly journals Social Isolation-Induced Decreases in Both the Abundance of Neuroactive Steroids and GABAA Receptor Function in Rat Brain

2002 ◽  
Vol 75 (2) ◽  
pp. 732-740 ◽  
Author(s):  
Mariangela Serra ◽  
Maria Giuseppina Pisu ◽  
Martino Littera ◽  
Giacomo Papi ◽  
Enrico Sanna ◽  
...  
Keyword(s):  
Rat Brain ◽  
Gabaa Receptor ◽  
Social Isolation ◽  
Neuroactive Steroids ◽  
Receptor Function

Subunit dependent modulation of GABAA receptor function by neuroactive steroids

1999 ◽  
Vol 819 (1-2) ◽  
pp. 75-82 ◽  
Author(s):  
Rajatavo Maitra ◽  
James N Reynolds
Keyword(s):  
Gabaa Receptor ◽  
Neuroactive Steroids ◽  
Receptor Function

Electrophysiological effects of various neuroactive steroids on the GABAA receptor in pituitary melanotrope cells

1997 ◽  
Vol 331 (2-3) ◽  
pp. 303-311 ◽  
Author(s):  
Frank Le Foll ◽  
Estelle Louiset ◽  
Hélène Castel ◽  
Hubert Vaudry ◽  
Lionel Cazin
Keyword(s):  
Gabaa Receptor ◽  
Neuroactive Steroids ◽  
Electrophysiological Effects

Modulation of GABAA receptor function by neuroactive steroids: evidence for heterogeneity of steroid sensitivity of recombinant GABAA receptor isoforms

1998 ◽  
Vol 76 (9) ◽  
pp. 909-920 ◽  
Author(s):  
Rajatavo Maitra ◽  
James N Reynolds
Keyword(s):  
Gabaa Receptor ◽  
Membrane Current ◽  
Neuroactive Steroids ◽  
Maximal Response ◽  
Gamma Aminobutyric Acid ◽  
Receptor Function ◽  
Gamma Subunit ◽  
Receptor Isoforms ◽  
Analgesic Agents ◽  
Gabaa Receptor Isoforms

Neuroactive steroids are potent, selective allosteric modulators of gamma-aminobutyric acid type A (GABAA) receptor function in the central nervous system, and may serve as endogenous anxiolytic and analgesic agents. In order to study the influence of subunit subtypes of the GABAA receptor on modulation of receptor function by neuroactive steroids, we expressed human recombinant GABAA receptors in Xenopus oocytes. GABA-activated membrane current, and the modulatory effects of the endogenous neurosteroid 5alpha-pregnan-3alpha-ol-20-one (allopregnanolone) and the synthetic steroid anesthetic 5alpha-pregnan-3alpha-ol-11,20-dione (alphaxalone) were measured using two-electrode voltage-clamp recording techniques. Allopregnanolone had similar effects to potentiate GABA-activated membrane current in the alpha1beta1gamma2L and alpha1beta2gamma2L receptor isoforms. In contrast, alphaxalone was much more effective as a positive allosteric modulator on the alpha1beta1gamma2L receptor isoform. In the absence of the gamma2L subunit subtype, allopregnanolone had much greater efficacy, but its potency was decreased. Allopregnanolone was much more effective on the alpha1beta1 receptor isoform compared with the alpha1beta2 receptor isoform. The potency for alphaxalone to potentiate the GABA response was not altered in the absence of the gamma2L subunit subtype, although its efficacy was greatly enhanced. Both allopregnanolone and alphaxalone produced nonparallel leftward shifts in the GABA concentration-response relationship in the absence of the gamma2L subunit, decreasing the EC50 concentration of GABA and increasing the maximal response. Only alphaxalone increased the maximal GABA response when the gamma2L subunit subtype was present. The 3beta-pregnane isomers epipregnanolone and isopregnanolone both inhibited the ability of allopregnanolone and alphaxalone to potentiate GABAA receptor function. However, the degree of block produced by the 3beta-pregnane steroid isomers was dependent on the type of receptor isoform studied and the neuroactive steroid tested. Isopregnanolone, the 3beta-isomer of allopregnanolone, was significantly more effective as a blocker of potentiation caused by allopregnanolone compared with alphaxalone in all receptor isoforms tested. Epipregnanolone had a greater efficacy as a blocker at the alpha1beta2gamma2L receptor isoform compared with the alpha1beta1gamma2L receptor isoform, and also produced a greater degree of block of potentiation caused by allopregnanolone compared with alphaxalone. Our results support the hypothesis that the heteromeric assembly of different GABAA receptor isoforms containing different subunit subtypes results in multiple steroid recognition sites on GABAA receptors, which in turn produces distinctly different modulatory interactions between neuroactive steroids acting at the GABAA receptor. The alpha and gamma subunit subtypes may have the greatest influence on allopregnanolone modulation of GABAA receptor function, whereas the beta and gamma subunit subtypes appear to be most important for the modulatory effects of alphaxalone.Key words: GABAA receptor, neurosteroid, allopregnanolone, alphaxalone, Xenopus oocyte.

scholarly journals Plasticity of GABAA Receptors during Pregnancy and Postpartum Period: From Gene to Function

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Valentina Licheri ◽  
Giuseppe Talani ◽  
Ashish A. Gorule ◽  
Maria Cristina Mostallino ◽  
Giovanni Biggio ◽  
...  
Keyword(s):  
Gabaa Receptor ◽  
Gabaa Receptors ◽  
Postpartum Period ◽  
Neuronal Excitability ◽  
Receptor Expression ◽  
Neuroactive Steroids ◽  
Receptor Function ◽  
Pregnancy And Postpartum ◽  
Sudden Decrease ◽  
New Treatments

Pregnancy needs complex pathways that together play a role in proper growth and protection of the fetus preventing its premature loss. Changes during pregnancy and postpartum period include the manifold machinery of neuroactive steroids that plays a crucial role in neuronal excitability by local modulation of specific inhibitory receptors: the GABAA receptors. Marked fluctuations in both blood and brain concentration of neuroactive steroids strongly contribute to GABAA receptor function and plasticity. In this review, we listed several interesting results regarding the regulation and plasticity of GABAA receptor function during pregnancy and postpartum period in rats. The increase in brain levels of neuroactive steroids during pregnancy and their sudden decrease immediately before delivery are causally related to changes in the expression/function of specific GABAA receptor subunits in the hippocampus. These data suggest that alterations in GABAA receptor expression and function may be related to neurological and psychiatric disorders associated with crucial periods in women. These findings could help to provide potential new treatments for these women’s disabling syndromes.

scholarly journals Ethanol-induced GABAA receptor alpha4 subunit plasticity involves phosphorylation and neuroactive steroids

2016 ◽  
Vol 72 ◽  
pp. 1-8 ◽  
Author(s):  
David F. Werner ◽  
Patrizia Porcu ◽  
Kevin N. Boyd ◽  
Todd K. O'Buckley ◽  
Jenna M. Carter ◽  
...  
Keyword(s):  
Gabaa Receptor ◽  
Neuroactive Steroids
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