Calcium release through IP3 receptors equips cells with a fast way to reprogram intracellular calcium signals.

SILVINA PONCE DAWSON

Conferencia; CNS 2020; 2020

Organization for Computational Neuroscience

Many intracellular calcium signals involve calcium release into thecytosol through inositol 1,4,5-trisphosphate (IP3) receptors(IP3Rs)/calcium channels. IP3Rs need to bind calcium and IP3 to becomeopen. Thus, IP3R-mediated calcium signals can spread through CalciumInduced Calcium Release (CICR) in which the calcium released throughan open channel induces the opening of neighboring ones. IP3Rs,however, are also inhibited by high calcium concentrations. Thisimplies that IP3Rs act as "coincidence" detectors where the timingbetween the relative increase of IP3 and calcium in their vicinityleads to signals that can propagate or remain spatially localized. Thenature of the resulting signal has implications for the subsequent endresponse. Thus, IP3R-mediated calcium release equips cells with a fastway to reprogram their responses. In this talk I will show modelingresults that highlight the role of this mechanism in synapticplasticity. In particular, I will show how the co-existence ofdifferent types of changes in homo and hetero-synapses induced bydifferent protocols can be explained in terms of the differential wayin which the IP3 and calcium concentrations increase and how thisimpacts on the resulting intracellular calcium signal beingpropagating or not.