Inhibitory circuit dysfunction as a potential contributor to cortical reorganization in Glioblastoma progression

Area of Science:

• Neuroscience
• Oncology
• Cellular Biology

Background:

• Glioblastoma (GBM) is an aggressive brain tumor infiltrating surrounding tissue.
• GBM significantly impacts adjacent cortical areas, leading to neurological deficits.

Purpose of the Study:

• To investigate GBM-induced plasticity changes in the peritumoral cortex.
• To understand how GBM affects motor mapping and cortical specificity.
• To identify molecular and functional alterations in inhibitory circuits.

Main Methods:

• Utilized two glioblastoma mouse models.
• Employed optogenetic stimulation for motor mapping.
• Analyzed morphological changes (dendritic spines, perineuronal nets, inhibitory markers).
• Assessed functional changes in inhibitory currents.

Main Results:

• GBM mice exhibited altered motor mapping and reduced cortical specificity.
• Observed a decrease in dendritic spines, perineuronal nets, and inhibitory markers.
• Found impaired inhibitory circuits with increased spontaneous inhibitory current frequency and decreased amplitude.
• Identified reduction in parvalbumin and somatostatin interneurons.

Conclusions:

• Inhibitory circuit disruption is critical for GBM-induced cortical reorganization and loss of motor map specificity.
• Maladaptive plasticity, driven by reduced inhibition and excitation/inhibition imbalance, increases seizure risk.
• Findings provide a basis for therapeutic strategies targeting inhibitory function restoration in GBM.