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How Theories Evolved Concerning The Mechanism Of Action Of Barbiturates, Wolfgang Löscher, Michael A. Rogawski
How Theories Evolved Concerning The Mechanism Of Action Of Barbiturates, Wolfgang Löscher, Michael A. Rogawski
Michael A. Rogawski
The barbiturate phenobarbital has been in use in the treatment of epilepsy for 100 years. It has long been recognized that barbiturates act by prolonging and potentiating the action of γ-aminobutyric acid (GABA) on GABA-A) receptors and at higher concentrations directly activating the receptors. A large body of data supports the concept that GABA-A) receptors are the primary central nervous system target for barbiturates, including the finding that transgenic mice with a point mutation in the β3 GABA-A)-receptor subunit exhibit diminished sensitivity to the sedative and immobilizing actions of the anesthetic barbiturate pentobarbital. Although phenobarbital is only modestly less potent …
Neurosteroids—Endogenous Regulators Of Seizure Susceptibility And Role In The Treatment Of Epilepsy, Doodipala S. Reddy, Michael A. Rogawski
Neurosteroids—Endogenous Regulators Of Seizure Susceptibility And Role In The Treatment Of Epilepsy, Doodipala S. Reddy, Michael A. Rogawski
Michael A. Rogawski
Certain steroid hormone metabolites that have activity as modulators of GABA-A receptors but lack conventional hormonal effects—including allopregnanolone and allotetrahydrodeoxycorticosterone—are synthesized within the brain, predominantly in principle (excitatory) neurons, and also in peripheral tissues. At low concentrations, such neurosteroids potentiate GABA-A receptor currents, whereas at higher concentrations they directly activate the receptor; large magnitude effects occur on nonsynaptic delta subunit-containing GABA-A receptors that mediate tonic currents. GABA-A receptor modulatory neurosteroids confer seizure protection in diverse animal models, without tolerance during chronic administration. Endogenous neurosteroids may play a role in catamenial epilepsy, stress-induced changes in seizure susceptibility, temporal lobe epilepsy, and …