Gephyrin-Lacking PV Synapses on Neocortical Pyramidal Neurons

Gephyrin has long been thought of as a master regulator for inhibitory synapses, acting as a scaffold to organize γ-aminobutyric acid type A receptors (GABAARs) at the post-synaptic density. Accordingly, gephyrin immunostaining has been used as an indicator of inhibitory synapses; despite this, the pan-synaptic localization of gephyrin to specific classes of inhibitory synapses has not been demonstrated. Genetically encoded fibronectin intrabodies generated with mRNA display (FingRs) against gephyrin (Gephyrin.FingR) reliably label endogenous gephyrin, and can be tagged with fluorophores for comprehensive synaptic quantitation and monitoring. Here we investigated input- and target-specific localization of gephyrin at a defined class of inhibitory synapse, using Gephyrin.FingR proteins tagged with EGFP in brain tissue from transgenic mice. Parvalbumin-expressing (PV) neuron presynaptic boutons labeled using Cre- dependent synaptophysin-tdTomato were aligned with postsynaptic Gephyrin.FingR puncta. We discovered that more than one-third of PV boutons adjacent to neocortical pyramidal (Pyr) cell somas lack postsynaptic gephyrin labeling. This finding was confirmed using correlative fluorescence and electron microscopy. Our findings suggest some inhibitory synapses may lack gephyrin. Gephyrin-lacking synapses may play an important role in dynamically regulating cell activity under different physiological conditions.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:22

Enthalten in:

International journal of molecular sciences - 22(2021), 18 vom: 17. Sept.

Sprache:

Englisch

Beteiligte Personen:

Kuljis, Dika A [VerfasserIn]
Micheva, Kristina D [VerfasserIn]
Ray, Ajit [VerfasserIn]
Wegner, Waja [VerfasserIn]
Bowman, Ryan [VerfasserIn]
Madison, Daniel V [VerfasserIn]
Willig, Katrin I [VerfasserIn]
Barth, Alison L [VerfasserIn]

Links:

Volltext

Themen:

Carrier Proteins
Correlative fluorescence and electron microscopy
Fluorescent protein sensors
GABAA receptors
Gephyrin
Intrabody
Journal Article
Light microscopy
Membrane Proteins
Optogenetics
Parvalbumin
Receptors, GABA-A
Synapses
Synaptophysin

Anmerkungen:

Date Completed 01.11.2021

Date Revised 11.11.2022

published: Electronic

Citation Status MEDLINE

doi:

10.3390/ijms221810032

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM331178079