Accumulating evidence indicates that astrocytes, classically considered to serve passive support roles, may play important functions in learning, memory, and information processing by actively modulating neuronal activity and synaptic function. Astrocytes respond to neurotransmitters released by synaptic terminals and modulate neuronal activity and synaptic transmission through the release of neuroactive substances, establishing a new signaling pathway relevant for information coding. However, little is known about the direct effect of astrocyte signaling on neuronal intrinsic properties and the excitability of neuronal networks beyond synapses. Brain neurons adjust their intrinsic membrane excitability to maintain the firing rate within their own optimal operational range. The homeostatic regulation of intrinsic excitability provides stability to the neural network in the face of dynamic and plastic synaptic inputs. How this complexity in the intrinsic property of neurons is essential to the normal function of an organism is not well understood. The general aim of this lecture is show whether activation of astrocytes regulates potassium conductance and, consequently, modulates neuronal intrinsic properties, modifying the hippocampal network excitability. This new perspective, will help to establish the existence of functional AstroNeuronal networks, which will change our view of the cellular elements involved in brain circuits. Finally, these results may reveal novel mechanisms involved in network dysfunctions and brain disorders related with neuronal hyper-excitability.

Ponencia científica organizada por el Programa de Neurociencias del Cima titulada "Control de la excitabilidad neuronal por los astrocitos. Importancia en la plasticidad del sistema nervioso" a cargo del Dr. Eduardo Daniel Martín, responsable del Laboratorio de Neurofisiología y Plasticidad Sináptica en el departamento de Neurobiología Funcional y de Sistemas, CSIC, Madrid.

Peer reviewed