Resting-state networks are spatially distributed, functionally connected brain regions. Studying these networks gives us information about the large-scale functional organization of the brain and alternations in these networks are considered to play a role in a wide range of neurological conditions and aging. To describe resting-state networks in dogs, we measured 22 awake, unrestrained animals of either sex and carried out group-level spatial independent component analysis to explore whole-brain connectivity patterns. Using resting-state functional magnetic resonance imaging (rs-fMRI), in this exploratory study we found multiple resting-state networks in dogs, which resemble the pattern described in humans. We report the following dog resting-state networks: default mode network (DMN), visual network (VIS), sensorimotor network (SMN), combined auditory (AUD)-saliency (SAL) network and cerebellar network (CER). The DMN, similarly to Primates, but unlike previous studies in dogs, showed antero-posterior connectedness with involvement of hippocampal and lateral temporal regions. The results give us insight into the resting-state networks of awake animals from a taxon beyond rodents through a non-invasive method.connectedness of the human default mode network was only found in superorder Euarchontoglires (primates and rodents), while the corresponding networks in superorder Laurasiatheria (described in ferrets 10 and dogs 9, 12 ) were reported to show antero-posterior dissociation. We aimed to investigate whether and if so, what kind of spatially distributed resting-state networks are detectable in a larger sample of awake, unrestrained family dogs in a resting state fMRI setup, following up on previous reports 9, 12 .
ResultsGroup-ICA decomposed the data into 20 independent components. ICASSO analysis returned a high stability index of the 20 estimate clusters (mean ±SD = 0.940 ±0.008), indicating high consistency across multiple ICA runs. Examination of the components resulted in retaining 6 components as signal components (spatially distributed networks with low frequency fluctuations, showing high correspondence with bilateral grey matter areas based on their spectral characteristics and spatial maps), while the remaining 14 components were classified as miscellaneous or noise. The excluded components, among others contained ventricular, susceptibility (located mainly in the frontal lobe, due to the extensive sinuses present in the dogs cranium) and motion artefacts. Signal components were primarily restricted to cortical areas. The resulting signal components were as follows:RSN A (Fig. 1): This resting-state network covered parts of the gyrus compositus rostralis, rostro-dorsal regions of the gyrus cinguli and the gyrus rectus; medial, bilateral caudal regions of the gyrus cinguli and gyrus splenialis, included bilaterally the hippocampus and gyrus parahippocampalis, the gyrus compositus caudalis, and caudoventral regions of the cerebellum. All of these regions correspond to regions indicated in the default mo...