Artículo del mes
abril 2021

Astrocyte-mediated switch in spike timing-dependent plasticity during hippocampal development

Referencia artículo:
Falcón-Moya, R., Pérez-Rodríguez, M., Prius-Mengual, J., Andrade-Talavera, Y., Arroyo-García, L. E., Pérez-Artés, R., ... & Rodríguez-Moreno, A. (2020). Astrocyte-mediated switch in spike timing-dependent plasticity during hippocampal development. Nature communications, 11(1), 1-14.
En este trabajo se ha descubierto que, durante el desarrollo postnatal, en el hipocampo, algunas de las formas de plasticidad que presenta (una depresión de larga duración, LTD) desaparece y de convierte en otra forma distinta de plasticidad (una potenciación de larga duración, LTP) conforme los animales (ratones) se van haciendo adultos y se han caracterizado en profundidad los mecanismos celulares y moleculares en los que los astrocitos desempeñan un papel central liberando glutamato y adenosina, revelando una nueva forma de LTP presináptica y las reglas para su inducción.
Resumen
Presynaptic spike timing-dependent long-term depression (t-LTD) at hippocampal CA3-CA1 synapses is evident until the 3rd postnatal week in mice, disappearing during the 4th week. At more mature stages, we found that the protocol that induced t-LTD induced t-LTP. We characterized this form of t-LTP and the mechanisms involved in its induction, as well as that driving this switch from t-LTD to t-LTP. We found that this t-LTP is expressed presynaptically at CA3-CA1 synapses, as witnessed by coefficient of variation, number of failures, paired-pulse ratio and miniature responses analysis. Additionally, this form of presynaptic t-LTP does not require NMDARs but the activation of mGluRs and the entry of Ca2+ into the postsynaptic neuron through L-type voltage-dependent Ca2+ channels and the release of Ca2+ from intracellular stores. Nitric oxide is also required as a messenger from the postsynaptic neuron. Crucially, the release of adenosine and glutamate by astrocytes is required for t-LTP induction and for the switch from t-LTD to t-LTP. Thus, we have discovered a developmental switch of synaptic transmission from t-LTD to t-LTP at hippocampal CA3-CA1 synapses in which astrocytes play a central role and revealed a form of presynaptic LTP and the rules for its induction
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