Prelude. Cycle 1. Introduction. Cycle 2. Structure defines function. Cycle 3. Diversity of cortical functions is provided by inhibition. Cycle 4. Windows on the brain. Cycle 5. A system of rhythms: from simple to complex dynamics. Cycle 6. Synchronization by oscillation. Cycle 7. The brain's default state: self-organized oscillations in rest and sleep. Cycle 8. Perturbation of the default patterns by experience. Cycle 9. The gamma buzz: gluing by oscillations in the waking brain. Cycle 10. Perceptions and actions are brain state-dependent. Cycle 11. Oscillations in the "other cortex:" navigation in real and memory space. Cycle 12. Coupling of systems by oscillations. Cycle 13. The tough problem. References.

Rhythms of the brain

Time in the biological sense is measured by cycles that range from milliseconds to years. Circadian rhythms, which measure time on a scale of 24 h, are generated by one of the most ubiquitous and well-studied timing systems. At the core of this timing mechanism is an intricate molecular mechanism that ticks away in many different tissues throughout the body. However, these independent rhythms are tamed by a master clock in the brain, which coordinates tissue-specific rhythms according to light input it receives from the outside world.

Coordination of circadian timing in mammals

/pdf/from-kuramoto-to-crawford-exploring-the-onset-of-3wpvjokr2x.pdf

From Kuramoto to Crawford: exploring the onset of synchronization in populations of coupled oscillators

Molecular Bases for Circadian Clocks

http://web.mit.edu/biophysics/papers/CELL2008.pdf

Nature, Nurture, or Chance: Stochastic Gene Expression and Its Consequences

Molecular Dissection of Two Distinct Actions of Melatonin on the Suprachiasmatic Circadian Clock

Cellular Construction of a Circadian Clock: Period Determination in the Suprachiasmatic Nuclei

GABA Synchronizes Clock Cells within the Suprachiasmatic Circadian Clock

The pineal hormone melatonin regulates seasonal reproduction and influences the timing of circadian rhythms. The Mel1a and Mel1b receptors are the high-affinity melatonin receptors present in mammals. Unexpectedly, the Mel1b receptor gene of the Siberian hamster, Phodopus sungorus, cannot encode a functional receptor; two nonsense mutations are present within the coding region. Southern blot analysis indicates that this is a single copy gene. The Mel1b receptor gene is nonfunctional in outbred populations of P. sungorus and Phodopus campbelli. Siberian hamsters lacking a functional Mel1b receptor nevertheless show seasonal reproductive and circadian responses to melatonin, indicating that the Mel1b receptor is not necessary for these responses. These data support the hypothesis that the Mel1a receptor, which does encode a functional receptor in this species, mediates reproductive and circadian responses to melatonin.

Chen Liu

Papers

Molecular Dissection of Two Distinct Actions of Melatonin on the Suprachiasmatic Circadian Clock

Cellular Construction of a Circadian Clock: Period Determination in the Suprachiasmatic Nuclei

GABA Synchronizes Clock Cells within the Suprachiasmatic Circadian Clock

Nature's knockout: the Mel1b receptor is not necessary for reproductive and circadian responses to melatonin in Siberian hamsters.