LFQ proteomics of mouse GABAergic interneurons during traumatic brain injury
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ABSTRACT: Unilateral Traumatic Brain Injury (TBI) causes functional disturbances of the neuronal networks spreading even to the undamaged cortical hemisphere. The phenomenon, referred to as transhemispheric diaschisis, is suggested to be mediated by an imbalance of the strength of glutamatergic, excitatory vs. GABAergic, inhibitory neurotransmission. Here we present evidence that a switch in expression of α Subunits of pore-forming L-Type voltage-gated calcium channels (VGCC), by an expression of CaV1.3 and simultaneous ablation of CaV1.2 in GABAergic interneurons could balance early cortical disturbances manifested as contralateral hyperexcitability in the early phase after TBI. The switch of the VGCC alpha Subunits in GABAergic interneurons was detected using the GAD67-GFP (Glutamate Decarboxylase 67 – Green Fluorescent Protein) Knock-in mouse line. Mice received a TBI with a Controlled Cortical Impact (CCI) to the primary motor and somatosensory cortex at postnatal day 19-21 under anesthesia in vivo. Single GFP+ interneurons located in the undamaged, contralateral cortex were isolated by Fluorescence-Activated Cell Sorting (FACS) and further analyzed by Mass Spectrometry (MS). The switch was associated with an increased excitability of Somatostatin (SST) interneurons and extracellular network activity in acute brain slices in Microelectrode Array (MEA) recordings, which could be restored in presence of isradipine (100 nM), which selectively blocks CaV1.3-containing VGCCs. These data suggest that a switch in alpha.subunits of VGCCs expressed on SST-positive interneurons stabilizes early hyperactivity of the contralateral cortical network at 72 h after TBI, thereby promoting an adaptive mechanism to counterbalance post-traumatic hyperexcitabilty that might lead to epileptogenesis.
INSTRUMENT(S): Synapt MS
ORGANISM(S): Mus Musculus (mouse)
TISSUE(S): Brain, Gabaergic Interneuron
DISEASE(S): Wounds And Injuries
SUBMITTER: Malte Sielaff
LAB HEAD: Stefan Tenzer
PROVIDER: PXD023551 | Pride | 2022-01-03
REPOSITORIES: Pride
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