Targeted Covalent Photoswitch for Two-Photon Control of Endogenous Receptors.

Area of Science:

• Neuroscience
• Biochemistry
• Optics

Background:

• Stimulating cells with light requires deep penetration and precision without damage.
• Current methods like optic fibers and external light sources are invasive or limited by light attenuation.
• Two-photon pharmacology offers precise cellular control using photoswitchable drugs and infrared laser light.

Purpose of the Study:

• To develop a two-photon optimized targeted covalent photoswitch (TCP2P) for precise cellular stimulation.
• To enable photopharmacology in wild-type animals without genetic modification.
• To control neuronal activity using a novel photoswitchable drug targeting endogenous receptors.

Main Methods:

• Developed TCP2P by combining ortho-fluoro-substituted azobenzene with conjugation ability.
• Utilized click coupling to prepare TCP2P from two precursor compounds.
• Applied TCP2P via simple incubation for controlling neuronal activity.

Main Results:

• TCP2P enables efficient two-photon isomerization.
• The photoswitch conjugates to nucleophilic residues of endogenous proteins (AMPA and kainate receptors).
• Neuronal activity was controlled with one- and two-photon excitation up to 800 nm without genetic modifications.

Conclusions:

• TCP2P is the first two-photon optimized targeted covalent photoswitch.
• This technology allows precise control of neuronal activity in wild-type animals.
• TCP2P offers a non-invasive method for studying neural circuits using photopharmacology.