NEUROCHEMISTRYPacemaker calcium oscillations in thalamic astrocytes in situParri, H. Rheinallt; Crunelli, VincenzoCAAuthor Information School of Biosciences, Cardiff University, Museum Avenue, PO Box 911, Cardiff, CF10 3US, UK CACorresponding Author Received 16 August 2001; accepted 3 October 2001 Neuroreport: December 21st, 2001 - Volume 12 - Issue 18 - p 3897-3900 Buy Abstract During development, astrocytes in the ventrobasal thalamus display spontaneous intracellular calcium [Ca2+]i oscillations, that can lead to the excitation of adjacent thalamocortical neurons via an NMDA receptor-mediated mechanism. In this study, we show that while astrocytes usually exhibit oscillations of irregular amplitude and frequency, a subset of spontaneously active thalamic astrocytes exhibits rhythmic, i.e. pacemaker, [Ca2+]i oscillations with an average frequency of 0.019 Hz. This frequency of the pacemaker oscillations is close to the modal frequency of the irregularly oscillating astrocytes, suggesting that there is a preferred frequency for astrocytic [Ca2+]i oscillations. If pacemaker [Ca2+]i oscillations underlie excitatory signaling to neurons, the result would be rhythmic activation of thalamocortical neurons and astrocyte-driven synchronized oscillations within neurons of the thalamocortical loop. © 2001 Lippincott Williams & Wilkins, Inc.