Ultradian corticosterone pulses balance glutamatergic transmission and synaptic plasticity.
Proc Natl Acad Sci U S A
; 111(39): 14265-70, 2014 Sep 30.
Article
en En
| MEDLINE
| ID: mdl-25225407
ABSTRACT
The rodent adrenal hormone corticosterone (CORT) reaches the brain in hourly ultradian pulses, with a steep rise in amplitude before awakening. The impact of a single CORT pulse on glutamatergic transmission is well documented, but it remains poorly understood how consecutive pulses impact on glutamate receptor trafficking and synaptic plasticity. By using high-resolution imaging and electrophysiological approaches, we report that a single pulse of CORT to hippocampal networks causes synaptic enrichment of glutamate receptors and increased responses to spontaneously released glutamatergic vesicles, collectively abrogating the ability to subsequently induce synaptic long-term potentiation. Strikingly, a second pulse of CORT one hour after the first--mimicking ultradian pulses--completely normalizes all aspects of glutamate transmission investigated, restoring the plastic range of the synapse. The effect of the second pulse is precisely timed and depends on a nongenomic glucocorticoid receptor-dependent pathway. This normalizing effect through a sequence of CORT pulses--as seen around awakening--may ensure that hippocampal glutamatergic synapses remain fully responsive and able to encode new stress-related information when daily activities start.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Corticosterona
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Transmisión Sináptica
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Ácido Glutámico
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Plasticidad Neuronal
Límite:
Animals
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2014
Tipo del documento:
Article