Awake whole-brain functional connectivity alterations in the adolescent spontaneously hypertensive rat feature visual streams and striatal networks

Brain mechanisms underpinning attention deficit/hyperactivity disorder (ADHD) are incompletely understood. The adolescent spontaneously hypertensive rat (SHR) is a widely studied preclinical model that expresses several of the key behavioral features associated with ADHD. Yet, little is known about large-scale functional connectivity patterns in the SHR, and their potential similarity to those of humans with ADHD. Using an approach comparable to human studies, magnetic resonance imaging in the awake animal was performed to identify whole-brain intrinsic neural connectivity patterns. An independent components analysis of resting-state functional connectivity demonstrated many common components between the SHR and both Wistar Kyoto and Sprague-Dawley control strains, but there was a divergence in other networks. In the SHR, three functional networks involving the striatum had only weak correlations with networks in the two control strains. Conversely, networks involving the visual cortex that was present in both control strains had only weak correlations with networks in the SHR. The implication is that the patterns of brain activity differ between the SHR and the other strains, suggesting that brain connectivity patterns in this animal model of ADHD may provide insights into the neural basis of ADHD. Brain connectivity patterns might also serve to identify brain circuits that could be targeted for the manipulation and evaluation of potential therapeutic options.