Non-invasive optogenetic stimulation method to regulate glucose metabolism in the liver and brown adipose tissue

1. A non-invasive optogenetic method for reducing a blood glucose level in a subject in need thereof, the method comprising:

injecting into a brown adipose tissue (BAT) of the subject an adeno-associated virus vector having a nucleic acid sequence encoding a transmembrane ion channel channelrhodopsin that is operably linked to a tyrosine hydroxylase (Th) promoter, wherein the transmembrane ion channel channelrhodopsin is activated by blue light having a wavelength of from 450 nm to 475 nm;

attaching one or more light-emitting modules of a light-emitting device directly above the skin of the subject that is adjacent to the brown adipose tissue, wherein the one or more light-emitting modules have no contact with a subcutaneous tissue under the skin adjacent to the brown adipose tissue; and

applying the blue light, generated from the light-emitting device, through the skin adjacent to the brown adipose tissue of the subject to activate the transmembrane ion channel channelrhodopsin in sympathetic adrenergic efferent nerve fibers in the brown adipose tissue and to reduce the blood glucose level in the subject, wherein the blue light at an intensity of 180 lumens is applied as a stimulation comprising a burst of 20 millisecond light pulses at 20 Hz for 1 second followed by a 3 second break, and wherein the stimulation is repeated for one hour.

2. The method of claim 1 , wherein activation of the transmembrane ion channel channelrhodopsin in the sympathetic adrenergic efferent nerve fibers further increasing BAT thermogenesis, core body temperature, or both.

3. The method of claim 2 , wherein the subject has type 2 diabetes, pre-diabetes or hyperglycemia.

4. The method of claim 1 , wherein the light-emitting device comprises a Transistor-Transistor Logic (TTL) pulse generator and a power supply.