Real Time Imaging and Dynamics of Hippocampal Zn2+ under Epileptic Condition Using a Ratiometric Fluorescent Probe

摘要

Zinc, the essential trace element in human body exists either in the bound or free state, for both structural and functional roles. Insights on Zn²⁺ distribution and its dynamics are essential in view of the fact that Zn²⁺ dyshomeostasis is a risk factor for epileptic seizures, Alzheimer’s disease, depression, etc. Herein, a bipyridine bridged bispyrrole (BP) probe is used for ratiometric imaging and quantification of Zn²⁺ in hippocampal slices. The green fluorescence emission of BP shifts towards red in the presence of Zn²⁺. The probe is used to detect and quantify the exogenous and endogenous Zn²⁺ in glioma cells and hippocampal slices. The dynamics of chelatable zinc ions during epileptic condition is studied in the hippocampal neurons, in vitro wherein the translocation of Zn²⁺ from presynaptic to postsynaptic neuronal bodies is imaged and ratiometrically quantified. Raman mapping technique is used to confirm the dynamics of Zn²⁺ under epileptic condition. Finally, the Zn²⁺ distribution was imaged in vivo in epileptic rats and the total Zn²⁺ in rat brain was quantified. The results favour the use of BP as an excellent Zn²⁺ imaging probe in biological system to understand the zinc associated diseases and their management.