TY - JOUR
T1 - Circadian waves of cytosolic calcium concentration and long-range network connections in rat suprachiasmatic nucleus
AU - Hong, Jin Hee
AU - Jeong, Byeongha
AU - Min, Cheol Hong
AU - Lee, Kyoung J.
PY - 2012/5
Y1 - 2012/5
N2 - The suprachiasmatic nucleus (SCN) is the master clock in mammals governing the daily physiological and behavioral rhythms. It is composed of thousands of clock cells with their own intrinsic periods varying over a wide range (20-28h). Despite this heterogeneity, an intact SCN maintains a coherent 24h periodic rhythm through some cell-to-cell coupling mechanisms. This study examined how the clock cells are connected to each other and how their phases are organized in space by monitoring the cytosolic free calcium ion concentration ([Ca 2+] c) of clock cells using the calcium-binding fluorescent protein, cameleon. Extensive analysis of 18 different organotypic slice cultures of the SCN showed that the SCN calcium dynamics is coordinated by phase-synchronizing networks of long-range neurites as well as by diffusively propagating phase waves. The networks appear quite extensive and far-reaching, and the clock cells connected by them exhibit heterogeneous responses in their amplitudes and periods of oscillation to tetrodotoxin treatments. Taken together, our study suggests that the network of long-range cellular connectivity has an important role for the SCN in achieving its phase and period coherence.
AB - The suprachiasmatic nucleus (SCN) is the master clock in mammals governing the daily physiological and behavioral rhythms. It is composed of thousands of clock cells with their own intrinsic periods varying over a wide range (20-28h). Despite this heterogeneity, an intact SCN maintains a coherent 24h periodic rhythm through some cell-to-cell coupling mechanisms. This study examined how the clock cells are connected to each other and how their phases are organized in space by monitoring the cytosolic free calcium ion concentration ([Ca 2+] c) of clock cells using the calcium-binding fluorescent protein, cameleon. Extensive analysis of 18 different organotypic slice cultures of the SCN showed that the SCN calcium dynamics is coordinated by phase-synchronizing networks of long-range neurites as well as by diffusively propagating phase waves. The networks appear quite extensive and far-reaching, and the clock cells connected by them exhibit heterogeneous responses in their amplitudes and periods of oscillation to tetrodotoxin treatments. Taken together, our study suggests that the network of long-range cellular connectivity has an important role for the SCN in achieving its phase and period coherence.
KW - Circadian oscillation
KW - Clock cell networks
KW - Phase waves and synchronization
KW - Suprachiasmatic nucleus calcium dynamics
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U2 - 10.1111/j.1460-9568.2012.08069.x
DO - 10.1111/j.1460-9568.2012.08069.x
M3 - Article
C2 - 22501027
AN - SCOPUS:84860673735
VL - 35
SP - 1417
EP - 1425
JO - European Journal of Neuroscience
JF - European Journal of Neuroscience
SN - 0953-816X
IS - 9
ER -