Simulation of spontaneous Ca2+ oscillations in astrocytes mediated by voltage-gated calcium channels.
The purpose of this computational study was to investigate the possible role of voltage-gated Ca(2+) channels in spontaneous Ca(2+) oscillations of astrocytes. By incorporating different types of voltage-gated Ca(2+) channels and a previous model, this study reproduced typical Ca(2+) oscillations in silico. Our model could mimic the oscillatory phenomenon under a wide range of experimental conditions, including resting membrane potential (-75 to -60 mV), extracellular Ca(2+) concentration (0.1 to 1500 muM), temperature (20 to 37 degrees C), and blocking specific Ca(2+) channels. By varying the experimental conditions, the amplitude and duration of Ca(2+) oscillations changed slightly (both <25%), while the frequency changed significantly ( approximately 400%). This indicates that spontaneous Ca(2+) oscillations in astrocytes might be an all-or-none process, which might be frequency-encoded in signaling. Moreover, the properties of Ca(2+) oscillations were found to be related to the dynamics of Ca(2+) influx, and not only to a constant influx. Therefore, calcium channels dynamics should be used in studying Ca(2+) oscillations. This work provides a platform to explore the still unclear mechanism of spontaneous Ca(2+) oscillations in astrocytes.
Zeng
Shuai
S
Britton Chance Center of Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China.
Li
Bing
B
Zeng
Shaoqun
S
Chen
Shangbin
S
D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D001703:Biophysics / Q000379:methods; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D003198:Computer Simulation; D006801:Humans; D015640:Ion Channel Gating; D007700:Kinetics; D008564:Membrane Potentials; D008954:Models, Biological; D009991:Oscillometry / Q000379:methods; D015398:Signal Transduction; D012984:Software; D013696:Temperature
D015220:Calcium Channels; D002118:Calcium