Nature neuroscience
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Nature neuroscience · Jan 2005
Electrical synapses coordinate activity in the suprachiasmatic nucleus.
In the suprachiasmatic nucleus (SCN), the master circadian pacemaker, neurons show circadian variations in firing frequency. There is also considerable synchrony of spiking across SCN neurons on a scale of milliseconds, but the mechanisms are poorly understood. Using paired whole-cell recordings, we have found that many neurons in the rat SCN communicate via electrical synapses. ⋯ In wild-type mice, as in rats, the SCN contained electrical synapses, but electrical synapses were absent in connexin36-knockout mice. The knockout mice also showed dampened circadian activity rhythms and a delayed onset of activity during transition to constant darkness. We suggest that electrical synapses in the SCN help to synchronize its spiking activity, and that such synchrony is necessary for normal circadian behavior.
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Nature neuroscience · Jan 2005
Traveling waves of activity in primary visual cortex during binocular rivalry.
When the two eyes view large, dissimilar patterns that induce binocular rivalry, alternating waves of visibility are experienced as one pattern sweeps the other out of conscious awareness. Here we combine psychophysics with functional magnetic resonance imaging to show tight linkage between dynamics of perceptual waves during rivalry and neural events in human primary visual cortex (V1).