Magnetogenetics was developed to remotely control genetically targeted neurons. A variant of magnetogenetics uses magnetic fields to activate transient receptor potential vanilloid (TRPV) channels when coupled with ferritin. Stimulation with static or RF magnetic fields of neurons expressing these channels induces Ca²⁺ transients and modulates behavior. However, the validity of ferritin-based magnetogenetics has been questioned due to controversies surrounding the underlying mechanisms and deficits in reproducibility. Here, we validated the magnetogenetic approach Ferritin-iron Redistribution to Ion Channels (FeRIC) using electrophysiological (Ephys) and imaging techniques. Previously, interference from RF stimulation rendered patch-clamp recordings inaccessible for magnetogenetics. We solved this limitation for FeRIC, and we studied the bioelectrical properties of neurons expressing TRPV4 (nonselective cation channel) and transmembrane member 16A (TMEM16A; chloride-permeable channel) coupled to ferritin (FeRIC channels) under RF stimulation. We used cultured neurons obtained from the rat hippocampus of either sex. We show that RF decreases the membrane resistance (Rm) and depolarizes the membrane potential in neurons expressing TRPV4^FeRIC. RF does not directly trigger action potential firing but increases the neuronal basal spiking frequency. In neurons expressing TMEM16A^FeRIC, RF decreases the Rm, hyperpolarizes the membrane potential, and decreases the spiking frequency. Additionally, we corroborated the previously described biochemical mechanism responsible for RF-induced activation of ferritin-coupled ion channels. We solved an enduring problem for ferritin-based magnetogenetics, obtaining direct Ephys evidence of RF-induced activation of ferritin-coupled ion channels. We found that RF does not yield instantaneous changes in neuronal membrane potentials. Instead, RF produces responses that are long-lasting and moderate, but effective in controlling the bioelectrical properties of neurons.

磁遗传学的发展是为了远程控制基因目标神经元。磁遗传学的一种变体使用磁场与铁蛋白结合时激活瞬时受体电位香草酸 (TRPV) 通道。用静态或射频磁场刺激表达这些通道的神经元会诱导 Ca ²⁺ 瞬变并调节行为。然而，由于围绕潜在机制的争议和重现性的缺陷，基于铁蛋白的磁遗传学的有效性受到质疑。在这里，我们使用电生理学 (Ephys) 和成像技术验证了磁遗传学方法铁蛋白-铁重新分布到离子通道 (FeRIC)。此前，射频刺激的干扰使得膜片钳记录无法用于磁遗传学。我们解决了 FeRIC 的这一局限性，并研究了在射频刺激下表达 TRPV4（非选择性阳离子通道）和与铁蛋白（FeRIC 通道）耦合的跨膜成员 16A（TMEM16A；氯离子渗透通道）的神经元的生物电特性。我们使用从任一性别的大鼠海马体中获得的培养神经元。我们发现 RF 降低了表达 TRPV4 ^FeRIC 的神经元中的膜电阻 (Rm) 并使膜电位去极化。射频不会直接触发动作电位放电，但会增加神经元基础尖峰频率。在表达 TMEM16A ^FeRIC 的神经元中，RF 降低 Rm，使膜电位超极化，并降低尖峰频率。此外，我们证实了先前描述的负责射频诱导铁蛋白耦合离子通道激活的生化机制。 我们解决了基于铁蛋白的磁遗传学的一个持久问题，获得了射频诱导铁蛋白耦合离子通道激活的直接 Ephys 证据。我们发现射频不会产生神经元膜电位的瞬时变化。相反，射频产生持久且温和的反应，但可以有效控制神经元的生物电特性。