Excitation wave propagation as a possible mechanism for signal transmission in pancreatic islets of Langerhans
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Excitation wave propagation as a possible mechanism for signal transmission in pancreatic islets of Langerhans. / Aslanidi, O V; Mornev, O A; Skyggebjerg, Ole; Arkhammar, P; Thastrup, Ole; Sørensen, M P; Christiansen, P L; Conradsen, Knut; Scott, Alwyn C.
In: Biophysical Journal, Vol. 80, No. 3, 2001, p. 1195-209.Research output: Contribution to journal › Journal article › Research › peer-review
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T1 - Excitation wave propagation as a possible mechanism for signal transmission in pancreatic islets of Langerhans
AU - Aslanidi, O V
AU - Mornev, O A
AU - Skyggebjerg, Ole
AU - Arkhammar, P
AU - Thastrup, Ole
AU - Sørensen, M P
AU - Christiansen, P L
AU - Conradsen, Knut
AU - Scott, Alwyn C.
PY - 2001
Y1 - 2001
N2 - In response to glucose application, beta-cells forming pancreatic islets of Langerhans start bursting oscillations of the membrane potential and intracellular calcium concentration, inducing insulin secretion by the cells. Until recently, it has been assumed that the bursting activity of beta-cells in a single islet of Langerhans is synchronized across the whole islet due to coupling between the cells. However, time delays of several seconds in the activity of distant cells are usually observed in the islets of Langerhans, indicating that electrical/calcium wave propagation through the islets can occur. This work presents both experimental and theoretical evidence for wave propagation in the islets of Langerhans. Experiments with Fura-2 fluorescence monitoring of spatiotemporal calcium dynamics in the islets have clearly shown such wave propagation. Furthermore, numerical simulations of the model describing a cluster of electrically coupled beta-cells have supported our view that the experimentally observed calcium waves are due to electric pulses propagating through the cluster. This point of view is also supported by independent experimental results. Based on the model equations, an approximate analytical expression for the wave velocity is introduced, indicating which parameters can alter the velocity. We point to the possible role of the observed waves as signals controlling the insulin secretion inside the islets of Langerhans, in particular, in the regions that cannot be reached by any external stimuli such as high glucose concentration outside the islets.
AB - In response to glucose application, beta-cells forming pancreatic islets of Langerhans start bursting oscillations of the membrane potential and intracellular calcium concentration, inducing insulin secretion by the cells. Until recently, it has been assumed that the bursting activity of beta-cells in a single islet of Langerhans is synchronized across the whole islet due to coupling between the cells. However, time delays of several seconds in the activity of distant cells are usually observed in the islets of Langerhans, indicating that electrical/calcium wave propagation through the islets can occur. This work presents both experimental and theoretical evidence for wave propagation in the islets of Langerhans. Experiments with Fura-2 fluorescence monitoring of spatiotemporal calcium dynamics in the islets have clearly shown such wave propagation. Furthermore, numerical simulations of the model describing a cluster of electrically coupled beta-cells have supported our view that the experimentally observed calcium waves are due to electric pulses propagating through the cluster. This point of view is also supported by independent experimental results. Based on the model equations, an approximate analytical expression for the wave velocity is introduced, indicating which parameters can alter the velocity. We point to the possible role of the observed waves as signals controlling the insulin secretion inside the islets of Langerhans, in particular, in the regions that cannot be reached by any external stimuli such as high glucose concentration outside the islets.
KW - Animals
KW - Calcium
KW - Calcium Signaling
KW - Islets of Langerhans
KW - Kinetics
KW - Mathematics
KW - Mice
KW - Mice, Inbred Strains
KW - Microscopy, Fluorescence
KW - Models, Biological
U2 - 10.1016/S0006-3495(01)76096-1
DO - 10.1016/S0006-3495(01)76096-1
M3 - Journal article
C2 - 11222284
VL - 80
SP - 1195
EP - 1209
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 3
ER -
ID: 43349067