HERNANDEZ-MORALES, M.; Morales-Zuniga, J.; Tran, T.; Han, V.; Tjahjono, N.; Natan, R. G.; Li, Y.; Tian, L.; Ji, N.; Liu, C.

Astrocytes exhibit complex calcium signaling proposed to detect, integrate, and modulate neuronal activity; however, their causal contribution to neural circuit function remains unresolved. This is partly due to the lack of tools that recapitulate physiological astrocyte calcium signaling. Here, we show that experimental magnetic control of endogenous calcium signaling in astrocytes is sufficient to modulate neural circuit dynamics. Using pmFeRIC, a magnetogenetic tool for remote, noninvasive, and on-demand activation of endogenous calcium pathways, we demonstrate that selective activation of astrocyte calcium signaling drives neuronal activity. pmFeRIC uses magnetic fields and endogenous ferritin to generate localized reactive oxygen species (ROS) at the plasma membrane, activating native ROS-sensitive ion channels, inducing calcium influx. In hippocampal circuits in vitro, magnetic activation of endogenous astrocytic calcium signaling produced robust, state-dependent changes in neuronal circuit activity, in part by increasing presynaptic release probability, postsynaptic burst firing, and glutamatergic transmission. These effects were mediated by transient receptor potential channels, amplified by intracellular calcium stores, and abolished when astrocyte calcium signaling was disrupted, establishing a causal role in neural circuit dynamics. In vivo, pmFeRIC activates endogenous calcium signaling in astrocytes with kinetics comparable to locomotion-induced activity, enabling control of astrocyte calcium dynamics that resemble physiological behavioral responses. Together, these findings establish that endogenous astrocytic calcium signaling is sufficient to modulate neural circuit function and introduce a broadly applicable platform for cell-specific, wireless, on-demand control of endogenous calcium signaling through magnetic activation of ROS-sensitive ion channels.