A photoswitchable GPCR-based opsin for presynaptic inhibition

Area of Science:

• Neuroscience
• Optogenetics
• Molecular Biology

Background:

• Optogenetic activation of neural circuits is established, but rapid and reversible synaptic inhibition remains challenging.
• Presynaptic G protein-coupled receptors (GPCRs) naturally inhibit synaptic transmission.
• Developing tools for precise control of neural activity is crucial for understanding brain function.

Purpose of the Study:

• To characterize parapinopsin (PPO) as a novel GPCR-based opsin for rapid and reversible presynaptic terminal inhibition.
• To evaluate PPO's efficacy in suppressing neurotransmitter release and influencing behavior in vivo.
• To establish PPO as a valuable tool for spatiotemporal control of inhibitory GPCR signaling.

Main Methods:

• Leveraging natural inhibitory presynaptic GPCRs to develop PPO.
• Characterizing PPO's photoswitchable properties (blue light activation, amber light inactivation).
• Assessing PPO's effect on glutamate, GABA, and dopamine release in presynaptic terminals.
• Investigating PPO's impact on reward behaviors in vivo.

Main Results:

• PPO is a photoswitchable opsin coupling to Gi/o signaling cascades.
• PPO enables rapid, reversible, and repeated inhibition of synaptic transmission.
• PPO effectively inhibits glutamate, GABA, and dopamine release presynaptically.
• In vivo, PPO reversibly alters reward behaviors in a time-locked manner.

Conclusions:

• Parapinopsin (PPO) provides a much-needed solution for rapid and reversible synaptic inhibition in neuroscience.
• PPO offers broad utility for spatiotemporal control of inhibitory GPCR signaling pathways.
• This optogenetic tool significantly enhances the ability to manipulate and study neural circuit dynamics.