The atypical adhesion GPCR ADGRA1 controls hippocampal inhibitory circuit function

Area of Science:

• Neuroscience
• Cell Biology
• Synaptic Plasticity

Background:

• Inhibitory interneurons are vital for neural circuit function.
• The specific receptors and pathways governing inhibitory synaptic function remain largely unknown.

Purpose of the Study:

• To identify novel cell surface receptors regulating inhibitory interneuron function in the hippocampus.
• To elucidate the role of the atypical adhesion GPCR ADGRA1 in hippocampal inhibitory circuits.

Main Methods:

• Utilized genetic deletion of ADGRA1 in specific hippocampal interneuron populations (PV and SST).
• Assessed synaptic function using electrophysiological recordings.
• Investigated downstream signaling pathways, including G protein coupling.

Main Results:

• ADGRA1 is selectively expressed in hippocampal PV and SST interneurons and localizes to synapses.
• Deletion of ADGRA1 in these interneurons impairs inhibitory synaptic transmission onto Dentate Gyrus granule cells.
• ADGRA1 deletion leads to deficits in learning and memory.
• ADGRA1 signaling involves Gα13, which is important for PV interneuron network formation.

Conclusions:

• ADGRA1 is essential for the synaptic function of hippocampal PV and SST interneurons.
• This study identifies a novel orphan receptor pathway regulating specific inhibitory synapse subtypes.
• The findings expand understanding of the molecular mechanisms underlying hippocampal inhibitory circuit development and function.