Modelling Cross Talk in the Spatiotemporal System Dynamics of Calcium, IP₃ and Nitric Oxide in Neuron Cells

The bioenergetic system of calcium ([Ca²⁺]), inositol 1, 4, 5-trisphophate (IP₃) and nitric oxide (NO) regulate the diverse mechanisms in neurons. The dysregulation in any or all of the calcium, IP₃ and nitric oxide dynamics may cause neurotoxicity and cell death. Few studies are noted in the literature on the interactions of two systems like [Ca²⁺] with IP₃ and [Ca²⁺] with nitric oxide in neuron cells, which gives limited insights into regulatory and dysregulatory processes in neuron cells. But, no study is available on the cross talk in dynamics of three systems [Ca²⁺], IP₃ and NO in neurons. Thus, the cross talk in the system dynamics of [Ca²⁺], IP₃ and NO regulation processes in neurons have been studied using mathematical model. The two-way feedback process between [Ca²⁺] and IP₃ and two-way feedback process between [Ca²⁺] and NO through cyclic guanosine monophosphate (cGMP) with plasmalemmal [Ca²⁺]-ATPase (PMCA) have been incorporated in the proposed model. This coupling handles the indirect two-way feedback process between IP₃ and nitric oxide in neuronal cells automatically. The numerical outcomes were acquired by employing the finite element method (FEM) with the Crank-Nicholson scheme (CNS). The present model incorporating the sodium-calcium exchanger (NCX) and voltage-gated calcium channel (VGCC) provides novel insights into the various regulatory and dysregulatory processes due to buffer, IP₃-receptor, ryanodine receptor, cGMP kinetics through PMCA channel, etc. and their impacts on the interactive spatiotemporal system dynamics of [Ca²⁺], IP₃ and NO in neurons. It is concluded that the behavior of different crucial mechanisms is quite different for interactions of two systems of [Ca²⁺] and NO and the interactions of three systems of [Ca²⁺], IP₃ and nitric oxide in neuronal cell due to mutual regulatory adjustments. The association of several neurological disorders with the alterations in calcium, IP₃ and NO has been explored in neurons.