Preserved functional networks in a hydrocephalic mouse

Abstract

Hydrocephalus is a brain condition characterized by enlarged ventricles, due to an excess of cerebrospinal fluid. Although it is known to affect cognition, development, gait, and mood, the impact of hydrocephalus on large-scale functional brain organization is poorly documented. Here, we present results on a single spontaneous occurrence of severe hydrocephalus observed in a 3xTgAD mouse, compared to a control cohort of 3xTgAD littermates. Resting-state functional magnetic resonance imaging analysis, carried out under light anesthesia, revealed the remarkable presence of functional connectivity (FC) resembling the common mouse resting-state networks (RSNs). Four main components were identified in the hydrocephalic mouse, attributable to the Default Mode network, Salience network, and sensorimotor networks. Characteristic features of the RSNs in the hydrocephalic mouse were found to be well preserved, both in spatial distribution and in FC magnitude, despite the severity of the pathology. This is the first documented case of resting-state fMRI conducted on a mouse affected by severe hydrocephalus. The surprising presence of resting-state networks was found to be comparable to littermate controls, highlighting a remarkable functional resilience in the hydrocephalic brain.