Fig. 8 Transgene-free magnetothermal regulation of fear behaviors in mice using FVIOs. (a) Endogenous TRPV1 expression in the CeA regions of transgene-free mice visualized by immunofluorescence. (b) Quantification of endogenous and exogenous TRPV1 expression in the CeA regions of transgenic and transgene-free mice (n = 4, means ± SEM). (c) Percentage of freezing time in transgene-free mice treated with different doses of FVIOs under AMF exposure (n = 3 to 5, means ± SEM).