Functional atlas of the awake rat brain: A neuroimaging study of rat brain specialization and integration

Abstract

Connectivity-based parcellation approaches present an innovative method to segregate the brain into functionally specialized regions. These approaches have significantly advanced our understanding of the human brain organization. However, parallel progress in animal research is sparse. Using resting-state fMRI data and a novel, data-driven parcellation method, we have obtained robust functional parcellations of the rat brain. These functional parcellations reveal the regional specialization of the rat brain, which exhibited high within-parcel homogeneity and high reproducibility across animals. Graph analysis of the whole-brain network constructed based on these functional parcels indicates that the rat brain has a topological organization similar to humans, characterized by both segregation and integration. Our study also provides compelling evidence that the cingulate cortex is a functional hub region conserved from rodents to humans. Together, this study has characterized the rat brain specialization and integration, and has significantly advanced our understanding of the rat brain organization. In addition, it is valuable for studies of comparative functional neuroanatomy in mammalian brains.

Dynamic Connectivity Patterns in Conscious and Unconscious Brain

“…Twenty-five adult male Long-Evans rats (300-500 g) were housed and maintained on a 12-h light-12-h dark schedule, and provided access to food and water ad libitum throughout the duration of the study. To minimize stress and motion during imaging at the awake state, animals were acclimated to the scanning environment for 7 days (described in Liang et al, 2011Liang et al, , 2012aLiang et al, , 2013Liang et al, , 2014Liang et al, , 2015bMa et al, 2016;Zhang et al, 2010). To do this, rats were restrained and placed in a mock MRI scanner, where prerecorded MRI sounds were played.…”

Time to wake up: Studying neurovascular coupling and brain-wide circuit function in the un-anesthetized animal

“…13b) (Liang et al, 2012a). Furthermore, whole-brain RSFC profiles can be used to produce connectivity-based functional parcellations of the rat brain, which exhibit high reproducibility across animals (Ma et al, 2016). Similarly, when locomotion-induced changes in CBV are fit with linear models, these fits are very reproducible across days (Huo et al, 2015a) (Fig.…”

The role of fMRI in drug development

“…Several groups identified functional networks in the rodent brain that align with known anatomical connectivity and are similar to analogous networks in the human brain [152–154]. These include a hippocampal–prefrontal system considered to be the rodent analog of the default mode network (DMN) [155–158], a frontolateral network (anatomically similar to the human ‘task-positive’ network and anticorrelated to the DMN [159]), and bilateral sensory and subcortical systems [160].…”