The Journal of Neuroscience, April 19, 2006, ():
Noradrenergic Activation Amplifies Bottom-Up and Top-Down Signal-to-Noise Ratios in Sensory Thalamus
J. Neurosci. Hirata et al.
26: 4426
Supplemental data
Files in this Data Supplement:
- supplemental material
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Supplemental Figure S1. Population data showing the effects of an α-adrenergic receptor antagonist (phentolamine) on signal-to-noise ratios of PW responses during noradrenergic activation. Comparison of spontaneous firing (Hz), PW responses measured as spikes per stimulus per 20-ms bin and signal-to-noise ratios for these responses. Note that norepinephrine decreases the spontaneous firing and significantly increases the signal-to-noise ratio of PW responses and these effects are reversed by phentolamine. Responses correspond to the number of spikes measured 20-ms after each stimulus for PW stimulation at 0.1 Hz.
- supplemental material
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Supplemental Figure S2. Population data showing the effects of muscrinic and α-adrenergic receptor antagonists on facilitation and signal-to-noise ratios of corticothalamic responses during cholinergic and noradrenergic activation.
A. Comparison of the amount of facilitation (upper panel) and signal-to-noise ratios (lower panel) between control, carbachol and addition of the muscarinic antagonist atropine. Atropine was substituted for carbachol producing an immediate reversal of the effects of carbachol. Facilitation for responses at different frequencies was calculated as the percent of responses at 0.1 Hz. The responses were measured by summing the spikes evoked during a 20-ms time window after the thalamic radiation stimulus. Statistical calculations were performed within subjects by comparing the effect of each drug with the control responses. Responses during atropine did not differ from those during control conditions.
B. Comparison of the amount of facilitation (upper panel) and signal-to-noise ratios (lower panel) between control, norepinephrine and addition of the α-adrenergic receptor antagonist phentolamine. Phentolamine reversed the enhancement of facilitation caused by norepinephrine. In fact, facilitation during phentolamine was smaller than during control conditions for the highest stimulation frequencies (20-40 Hz). This was caused by an increase in the responses to low frequency stimulation, including 0.1 Hz, which leads to less facilitation.
- supplemental material
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Supplemental Figure S3. Effect of norepinephrine on inter-spike intervals and autocorrelations of an nRt cell.
A. Waveform of the recorded nRt spike.
B. Inter-spike interval histograms (IETH) calculated during two periods of spontaneous firing corresponding to application of ACSF and application of norepinephrine. Each period is 10 min. Note that the peak of the interval firing during the control period is ~ 5 ms, which corresponds to high frequency bursts (~5 spikes/burst), while during the norepinephrine period the interval was ~12 ms, which corresponds to high frequency tonic firing. Note also that during norepinephrine the number of counts is much larger consistent with a constant tonic firing mode.
C. Autocorrelation histograms for the same periods shown in B. During the control period the cell displays bursts that on occasion recur at ~10 Hz, which is the intrinsic bursting (spindling) frequency of the nRt. During norepinephrine the cell fires in a tonic fashion at high frequency.
