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A Role for Picomolar Concentrations of Pregnenolone Sulfate in Synaptic Activity-Dependent Ca2+ Signaling and CREB Activation
- Publication Year :
- 2014
- Publisher :
- The American Society for Pharmacology and Experimental Therapeutics, 2014.
-
Abstract
- Fast excitatory synaptic transmission that is contingent upon N-methyl d-aspartate receptor (NMDAR) function contributes to core information flow in the central nervous system and to the plasticity of neural circuits that underlie cognition. Hypoactivity of excitatory NMDAR-mediated neurotransmission is hypothesized to underlie the pathophysiology of schizophrenia, including the associated cognitive deficits. The neurosteroid pregnenolone (PREG) and its metabolites pregnenolone sulfate (PregS) and allopregnanolone in serum are inversely associated with cognitive improvements after oral PREG therapy, raising the possibility that brain neurosteroid levels may be modulated therapeutically. PregS is derived from PREG, the precursor of all neurosteroids, via a single sulfation step and is present at low nanomolar concentrations in the central nervous system. PregS, but not PREG, augments long-term potentiation and cognitive performance in animal models of learning and memory. In this report, we communicate the first observation that PregS, but not PREG, is a potent (EC50 ∼2 pM) enhancer of intracellular Ca(2+) that is contingent upon neuronal activity, NMDAR-mediated synaptic activity, and L-type Ca(2+) channel activity. Low picomolar PregS similarly activates cAMP response element-binding protein (CREB) phosphorylation (within 10 minutes), an essential memory molecule, via an extracellular-signal-regulated kinase/mitogen-activated protein kinase signal transduction pathway. Taken together, the results are consistent with a novel biologic role for the neurosteroid PregS that acts at picomolar concentrations to intensify the intracellular response to glutamatergic signaling at synaptic but not extrasynaptic, NMDARs by differentially augmenting CREB activation. This provides a genomic signal transduction mechanism by which PregS could participate in memory consolidation of relevance to cognitive function.
- Subjects :
- Male
medicine.medical_specialty
Neuroactive steroid
Calcium Channels, L-Type
MAP Kinase Signaling System
Neurotransmission
Biology
CREB
Rats, Sprague-Dawley
chemistry.chemical_compound
Inhibitory Concentration 50
Internal medicine
medicine
Animals
Calcium Signaling
Cyclic AMP Response Element-Binding Protein
Cells, Cultured
Pharmacology
Long-term potentiation
Articles
Synaptic Potentials
Rats
Endocrinology
chemistry
Pregnenolone
Synapses
biology.protein
Molecular Medicine
NMDA receptor
Memory consolidation
Pregnenolone sulfate
Neuroscience
medicine.drug
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....9a560b0ce386fb50bad3c2fe65de913d