Browsing by Author "Varga, Áron Bendegúz"

Cranial windows are commonly used in neuroscience for direct brain access, but they require skull removal which can lead to neuroinflammation, potentially affecting experiment outcomes. As the nature of the window varies from experiment to experiment along with parallel treatments, it is of particular interest to map the quality and extent of the resulting brain inflammation on a case-by-case basis to have a better understanding of inflammation-related confounding factors in future experiments. As the focus of our future experiments is on finding electrophysiological biomarkers of depression employing state-of-the-art in vivo electrophysiological tools through a cranial window, we would like to characterise the extent of inflammation linked to the cranial window of interest in a mouse model of depression. To achieve this, we implanted mice with a soft cranial window and afterwards, treated them with corticosterone for a month. The animals were sacrificed and astrocytic glial fibrillary acidic protein (GFAP) and microglial ionized calcium-binding adapter molecule 1 (IBA) were labelled on coronal brain sections and imaged using a confocal microscope. We quantified the percentage of GFAP+ and IBA+ pixels on brain slices as measures of neuroinflammation using an automatic global thresholding-based approach and a semi-automatised machine-learning-based approach of the QUINT workflow. Our thresholding-based analysis revealed a significant elevation in GFAP-positive pixels, indicative of astrogliosis, in mice subjected to both cranial window implantation and corticosterone treatment compared to controls. However, no significant changes in microglial reactivity were observed under similar conditions. Importantly, it appears that the cranial window alone did not evoke long-lasting brain inflammation and corticosterone only slightly affected astrocytic reactivity. And despite results using the QUINT workflow presented some confounds, our results provide important considerations for future experiments employing a combination of soft cranial window and chronic corticosterone treatment, but more research is needed to enhance the generalisability of our findings.