Journal: The Journal of Neuroscience

Article Title: Astrocyte-Mediated Neuronal Synchronization Properties Revealed by False Gliotransmitter Release

doi: 10.1523/JNEUROSCI.2761-16.2017

Figure Lengend Snippet: SIC-induced neuronal calcium signaling. A , Fluorescence image of a cortical slice loaded with Fluo-4AM (left) and SR101. Middle, Overlaid green and red images show the area at a time at beginning of acquisition (Frame a) and during a synchronized event (Frame b), with square bounded region delineating an area exhibiting a calcium increase in cells not SR101 loaded. Right, Active regions expanded. B , Fluorescence image of a field of neurons in a cortical slice loaded with Fluo-4 AM (left) and traces of fluorescence over time with spontaneous SCRs (right) for circled neurons in the presence of TTX. Scale bar, 50 μm. Top, Data from a slice preexposed in control aCSF. Bottom, Slice preexposed with D-Asp. C , Summary data of SCR frequency in control and D-Asp preexposed slices from barrel cortex, CA1 hippocampus, and VB thalamus illustrating their sensitivity to AP5. D , Patch-clamped neuron in the presence of TTX with pipette containing Fluo-4. The images on the left illustrate fluorescence before and at peak of the SCR. Traces show a spontaneous recorded SIC (top) and elicited fluorescence SCR (bottom). E , Patched neuron with pipette containing Fluo-4 recorded in current-clamp mode. Traces show a spontaneous burst (top) and elicited fluorescence calcium signal (bottom). F , Spontaneous SCRs from single-neuron patch-clamp recordings (top, blue traces) normalized to amplitude to illustrate kinetics. Middle traces (green) show example spontaneous SCRs from Fluo-4 AM-loaded slices in TTX. Gray lines represent individual SCRs; colored lines, the mean. Bottom traces show the mean traces from the two conditions superimposed with symbols illustrating SEM. G , Top trace shows responses in a patch-clamped neuron to injection of recorded SIC waveforms. Middle trace shows a neuron response to the SICs in current-clamp mode, with expanded action potentials in numbered responses to the left. Red bottom trace shows fluorescence changes during the SIC evoked events. H , Nest of calcium responses normalized to peak amplitude generated by injected SICs (red) and generated by spontaneous SICs (blue) with averaged comparison to the right.

Article Snippet: For combined electrophysiological and imaging experiments, EGTA was replaced with penta-potassium Fluo-4 100 μ m . Currents were recorded using a Multiclamp 700B amplifier and data were acquired and analyzed using PClamp 9 (Molecular Devices).

Techniques: Fluorescence, Transferring, Patch Clamp, Injection, Generated

Journal: The Journal of Neuroscience

Article Title: Astrocyte-Mediated Neuronal Synchronization Properties Revealed by False Gliotransmitter Release

doi: 10.1523/JNEUROSCI.2761-16.2017

Figure Lengend Snippet: Astrocyte-induced synchronized neuronal responses. A , Fluorescence images of Fluo-4 loaded slices of cortex, CA1 hippocampus, and VB thalamus. Neurons exhibiting calcium elevations are circled. Fluorescence over time traces for the neurons are displayed on the right in the presence of TTX and after the addition of AP5. Traces in red are those exhibiting a synchronized elevation in red circled cells in image. Slices were preexposed with D-Asp for 2-4 h B . Raster plots of SCRs recorded in neurons from the slices in A in the presence of TTX. Individual SCRs are denoted as points. Activated neurons are numbered vertically on the y -axis. The red bars indicate the example synchronous responses from A . C , Raster plot generated using the simulated probability model for 20 neurons. D , Bar graphs displaying relative proportion of synchronized events composed of different neuron numbers in slices from the different brain areas. E , Bar graph showing comparison of proportion of synchronous neuron groups of three neurons or more compared with the simulated probability model of random release with the same SCR frequency. F , Abrogating effect of AP5 on neuronal synchronization.

Article Snippet: For combined electrophysiological and imaging experiments, EGTA was replaced with penta-potassium Fluo-4 100 μ m . Currents were recorded using a Multiclamp 700B amplifier and data were acquired and analyzed using PClamp 9 (Molecular Devices).

Techniques: Fluorescence, Generated

Journal: The Journal of Neuroscience

Article Title: Astrocyte-Mediated Neuronal Synchronization Properties Revealed by False Gliotransmitter Release

doi: 10.1523/JNEUROSCI.2761-16.2017

Figure Lengend Snippet: Spatial extent of synchronized neuronal activity. A , Images of Fluo-4-AM-loaded slices from cortex, CA1 hippocampus, and VB thalamus. Same colored circles designate neurons that displayed event synchronization. Top images indicate two examplar synchronized groups for each area. Bottom images indicate for these exemplar cells those that exhibit synchronized elevations (circled) and neurons that participate in multiple synchronized groups (dotted circles) Scale bar, 50 μm. B , 3D plots with colored circles indicating synchronized neurons. Shading illustrates area encompassed by events ( x–y ) and vertical axis z shows the emergence of synchronized neurons and slice areas over time. C , Plots of average distance between neurons in a synchronized group in the different brain regions. Cumulative probability plot (right) of distance between synchronized neurons. Bottom, Bar graph of relative proportion of neurons in different brain areas participating in multiple synchronized events during the recording period. D , Interpretation of synchronization data: a single astrocyte (dark blue) releases GT, which activates and so synchronizes multiple neurons (dark orange). E , Depiction of “hub” neuron data interpretation: a single neuron can be activated by GT release from multiple astrocytes, each of which activate a different complement of the local neuronal population.

Article Snippet: For combined electrophysiological and imaging experiments, EGTA was replaced with penta-potassium Fluo-4 100 μ m . Currents were recorded using a Multiclamp 700B amplifier and data were acquired and analyzed using PClamp 9 (Molecular Devices).

Techniques: Activity Assay