Neuron stimulation by Quantum Mechanics
Neuron stimulation by temperatures thought benign by heating nanoparticles is in fact risky as quantum mechanics requires the emission of UV radiation that damages DNA and if not repaired by the immune system may cause cancer
NPs used in cancer therapy are thought to target and destroy malignant cells by heating with IR lasers to temperatures > 43 °C, the process called photodynamic therapy. NPs stand for nanoparticles. Typically, gold NPs are functionalized with molecules that bind to the cancer cell. But neuron stimulation by IR radiation directed to degenerative diseases of the eye differs from photodynamic cancer therapy in that only low temperatures < 10 °C are required. Upon heating the NPs by IR lasers, neurons are thought  to induce action potentials by temperature increases that change the capacitance of the lipid bilayer. Deep brain stimulations  in treating neurological disorders differ as temperatures > 43 °C require magnetic iron oxide NPs heated by 100 kHz - 1 MHz radiation because of the greater penetration required. DNA damage in neuron stimulation is not reported as temperature increases in heating NPs are considerd benign.
Regardless, NPs are not needed to stimulate neurons.
Indeed, it is well known IR radiation alone in the absence of NPs is sufficient for neuron stimulation, and if so, NPs would not be necessary thereby obviating collateral DNA damage. Recently, IR heating without NPs of the local aqueous medium adjacent the lipid bilayer of the neuron plasma membrane was found  sufficient to elicit action potentials.GCS simulations for the capacitance of a lipid membrane in electrolyte solution combining the core capacitance of the phospholipid bilayer and the ionic double layers on each side of the membrane were found to reasonably approximate the NP-free action potentials. GCS stands for Gouy-Chapman-
In neuron stimulation as well as photodynamic cancer therapy, classical physics is assumed with conservation of IR heat proceeding by increasing the temperature of the NPs or the lipid bilayer of the plasma membranes. However, QM governs the nanoscale and not classical physics. QM stands for quantum mechanics. By QM, the heated NP or bilayer cannot increase in temperature because the atoms lack heat capacity. Indeed, temperature changes do not occur in NPs and lipid bilayers, and instead EM radiation is created to induce charge by which the lipid bilayer is destabilized and disintegrates to create NPs - externally supplied NPs are not required!
Moreover, the classical GCS theory is not valid by QM to simulate bilayer capacitance. Simply stated, neurons cannot be excited by temperature. A QM mechanism is suggested to stimulate neurons.
The macroscopic world in which we live is governed by classical physics where the atom always has heat capacity, i.e., heating anything causes its temperature to increase. But in the nanoscopic world governed by the Planck law of QM, the heat capacity of the atoms in NPs or the lipid bilayer vanishes at nanoscale EM wavelengths as depicted at 300 °K in the thumbnail. EM stands for electromagnetic.Classical physics is applicable for EM confinement wavelengths λ > 100 microns as shown in the thumbnail. But for QM with λ < 100 microns, the heat capacity is reduced. High EM confinement, say for λ < 1 microns, is assured in NPs having diameters d < 100 nm and bilayer thicknesses d < 5 nm because their high surface-to-volume ratios confine the absorbed heat to short wavelengths λ < 100 nm. Since temperatures cannot increase by QM, conservation proceeds by QED converting the surface heat into standing EM radiation having half- wavelength λ / 2 = nd, where n and d are the refractive index and diameter of the NP.
QED stands for quantum electrodynamics, a simple form of light-matter interaction in the complex QED theory advanced by Feynman and others. Once the surface heat is expended in forming the standing EM radiation, the corresponding EM confinement vanishes allowing the standing EM radiation to be available to destroy cancer cells and stimulate neurons. See diverse QED applications at http://www.nanoqed.org, 2010 - 2016.
The QED induced EM radiation beyond the UV produced upon absorbing heat in NPs < 100 nm is proposed as the mechanism that stimulates neurons as well as destroying cancer cells in photodynamic therapy. QM precludes temperatures produced by heating NPs as the mechanism of neuron stimulation.
IR radiation alone does not avoid the question of DNA damage without NPs as the lipid bilayer itself creates its own NPs upon disintegrating under charge created by QED induced radiation.
QED radiation induced radiation produced during NP induced heating unequivocally damages the DNA and may cause cancer if the immune system cannot repair the DNA damage.
Nanotechnology is silent on DNA damage in IR radiation of NPs. Indeed, collateral DNA damage is not reported anywhere in the voluminous literature citing the positive effects of NPs in destroying cancer. Silence on the danger of NPs while emphasizing the positive effects of destroying cancer by otherwise benign temperature increases and not by EM radiation at UV or beyond levels may be a convenient way of extending research funding, but by ignoring collateral DNA damage is heading down a blind-alley in future clinical applications.
 J. L. Carvalho-de-
 R. Chen, et al., "Wireless magnetothermal deep brain stimulation,"
 M. G. Shapiro,et al, "Infrared light excites cells by changing their electrical capacitance,"