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Explore rhythmic brain activities and frequency responses in wake-sleep transitions. Discover the role of brain rhythms in cognitive functions and somatosensory processing during different sleep stages.
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Dynamic changes of somatosensory evoked potentials in rats and humans during wake-sleep states Institute of Cognitive Science, National Cheng Kung University 國立成功大學 認知科學所 蕭富仁 (Fu-Zen Shaw)
Biological rhythm • Rhythms are ubiquitous in the mammalian CNS. They also span a broad range of frequencies, from 100 Hz EEG to once per year (0.00000003 Hz) for many seasonal behaviors. They also influence the physiological states (respiratory and cardiac rhythms). • The earth is a rhythmic environment. • Brains have evolved a variety of systems for rhythmic control. (e.g., waking and sleep, cardiac rhythm, breathing cycle)
Brain rhythms • Alpha rhythm (8-13 Hz) appears at the occipital cortex when eyes close. [resting condition] {rolandic mu rhythm; temporal tau rhythm} • Beta rhythm (13-30 Hz) is associated with alertness. • Gamma rhythm (30-80 Hz) is related to sensory integration and feature binding. • Theta rhythm (4-8 or 4-10 Hz) • Delta rhythm (0.5-4 or 1-4 Hz) • Sleep spindle (12-15 Hz or 7-15 Hz) {sigma rhythm} • K complex (<0.5 Hz) {(very) slow oscillation}
Successive EEG changes throughout the sleep onset period Ogilvie, Sleep Med. Rev., 5, 247-270, 2001.
Characteristic patterns of the brain activities in the neocortex and hippocampus Buzsaki, Neuroscience, 31, 551-70, 1989. Gottesmann, Neurosci. Biobehav. Rev., 16, 31-8, 1992. Steriade et al., Science, 262, 679-85, 1993. Steriade, Neuroscience, 101, 243-76, 2000.
Brain rhythms in wake-sleep states Shaw et al., Sleep, 29, 276-284, 2006.
SEP changes during wake-sleep states Shaw et al., Sleep, 29, 276-284, 2006.
Frequency response of EPs Castro-Alamancos, Prog. Neurobiol., 74, 213-247, 2004.
Augmenting response in cortical neurons during 80-150 ms inter-stimulus intervals Castro-Alamancos and Connors, Science, 272, 274-277, 1996.
Short-term plasticity:Augmenting response in cortical neurons by 10-Hz stimulation Steriade, Trends Neurosci., 22, 337-345, 1999.
Frequency response of SEPs in wake-sleep states Shaw et al., Sleep, 29, 276-284, 2006.
SEP changes in sleep and absence epilepsy Shaw et al., Sleep, 29, 276-284, 2006.
Two gamma responses: evoked vs. induced Tallon-Baudry and Bertrand, Trends Cog. Sci., 3, 151-162, 1999.
Tallon-Baudry and Bertrand, Trends Cog. Sci., 3, 151-162, 1999.
Eevoked auditory gamma activity during wake-sleep states Spontaneous Evoked responses Llinas and Ribary, Proc. Natl. Acad. Sci. USA, 90, 2078-2081, 1993.
Evoked visual gamma activity in various brain areas Schurmann et al., NeuroReport, 8, 531-534, 1997.
Evoked auditory gamma activity in various brain areas Basar et al., IEEE Eng. Bio. Med., 14, 400-410, 1995. Shaw and Chew, Brain Res., 983: 152-161, 2003.
Gamma responses of the rat’s SEPs in wake-sleep states Shaw and Chew, Brain Res., 983: 152-163, 2003.
Gamma responses of the rat’s SEPs in wake-sleep states Shaw and Chew, Brain Res., 983: 152-163, 2003.
Changes of cortical somatosensory evoked potentials using medial nerve stimulation during wake-sleep states
2 1 P1 N1 + - *P <.05 vs S2; #P <.05 vs SWS; +P <.05 vs REM by Student-Newman-Keuls test.
The role of sleep in brain plasticity Dual process: SWS is favorable to explicit memory traces REM sleep is involved in implicit memory consolidation Double-step process: Consolidation of memory traces requires SWS followed by REM sleep Two-stage processes to external stimulation: SWS (sleep spindle) is beneficial for enhancement of inputs, and REM sleep for integrating/binding inputs. Maquet, Science, 294, 1048-1052, 2001.
Acknowledgement National Cheng Kung University S.-F. Liang (梁勝富) National Taiwan University C.-T. Yen (嚴震東) Graduate Students J.-H. Chew (周佳禾) S.-Y. Lee (李姝瑩) T.-Y. Chuang (莊子宜)