Non-invasive, opsin-free mid-infrared modulation activates cortical neurons and accelerates associative learning

Abstract

Neurostimulant drugs or magnetic/electrical stimulation techniques can overcome attention deficits, but these drugs or techniques are weakly beneficial in boosting the learning capabilities of healthy subjects. Here, we report a stimulation technique, mid-infrared modulation (MIM), that delivers mid-infrared light energy through the opened skull or even non-invasively through a thinned intact skull and can activate brain neurons in vivo without introducing any exogeneous gene. Using c-Fos immunohistochemistry, in vivo single-cell electrophysiology and two-photon Ca2+ imaging in mice, we demonstrate that MIM significantly induces firing activities of neurons in the targeted cortical area. Moreover, mice that receive MIM targeting to the auditory cortex during an auditory associative learning task exhibit a faster learning speed (~50% faster) than control mice. Together, this non-invasive, opsin-free MIM technique is demonstrated with potential for modulating neuronal activity.

Inhibition of Cancer Cell Migration and Glycolysis by Terahertz Wave Modulation via Altered Chromatin Accessibility

“…We revealed greatly enhanced permeability of ion channels [34] and accelerated unwinding of DNA duplexes [35] and reduced receptor-ligand binding [36] under specific THM stimuli. Later, we experimentally achieved reversibly shortened action potential (AP) waveforms [37] and modulated the activity of neurons in targeted brain cortical areas by THM [38]. All these results indicate the regulatory role of THM on the biomolecules.…”

Reversible and gain modulation of neuronal responses and sensorimotor behavior by mid-infrared stimulation

“…MIRS can exert non-thermal effects on ion channels, and lead to gain modulation of action potentials based on current injections in vitro brain slices (Liu, et al, 2021). MIRS can enhance neuronal spontaneous activities (Zhang, et al, 2021) and sensory responses (Tan, et al, 2021) in anesthetized animals. 2) behavioral performance .…”

“…2) behavioral performance . MIRS can effectively modulate behavior by accelerating associative learning in mice (Zhang, et al, 2021), and regulating startle responses in larval zebrafish (Liu, et al, 2021). Although our understanding of how MIRS neuromodulation impacts the brain is evolving, it is still left vacant to demonstrate how MIRS alters neuronal firing in brain network, and then how the alternation guides behavioral performance for lack of simultaneous recording in awake-behaving animals.…”

Dielectric dispersion characteristics of the phospholipid bilayer with subnanometer resolution from terahertz to mid-infrared

“…The electromagnetic spectrum from terahertz to mid-infrared region is vital to living organisms since the collective vibrations of most biomacromolecules (e.g., DNA and protein) fall within this frequency range, where many significant physiological phenomena and biomedical applications have been reported ( Barone et al, 2005 ; Kitagawa et al, 2006 ; Rodrigo et al, 2015 ; Cheon et al, 2016 ; Turker-Kaya and Huck, 2017 ; Mittal et al, 2018 ; Zhu et al, 2021 ; Zhang et al, 2021 ; Li et al, 2021 ; Li et al, 2022 ; Sun et al, 2022 ). In addition, the spectra of the optical constant (refractive index and extinction coefficient), and the dielectric constant (real and imaginary parts of the permittivity) of all biomaterials contain the inherent information of their internal molecules, atoms and chemical bonds, and hence could be utilized as the functional biosignatures ( Pethig and Kell, 1987 ; Parthasarathy et al, 2005 ; Davidov et al, 2021 ).…”