Anterior–posterior dissociation of the default mode network in dogs

Abstract

The default mode network (DMN) in humans has been extensively studied using seed-based correlation analysis (SCA) and independent component analysis (ICA). While DMN has been observed in monkeys as well, there are conflicting reports on whether they exist in rodents. Dogs are higher mammals than rodents, but cognitively not as advanced as monkeys and humans. Therefore, they are an interesting species in the evolutionary hierarchy for probing the comparative functions of the DMN across species. In this study, we sought to know whether the DMN, and consequently its functions such as self-referential processing, are exclusive to humans/monkeys or can we also observe the DMN in animals such as dogs. To address this issue, resting state functional MRI data from the brains of lightly sedated dogs and unconstrained and fully awake dogs were acquired, and ICA and SCA were performed for identifying the DMN. Since anesthesia can alter resting state networks, confirming our results in awake dogs was essential. Awake dog imaging was accomplished by training the dogs to keep their head still using reinforcement behavioral adaptation techniques. We found that the anterior (such as anterior cingulate and medial frontal) and posterior regions (such as posterior cingulate) of the DMN were dissociated in both awake and anesthetized dogs.

Brain structure–function associations identified in large-scale neuroimaging data

“…1). The gRAICAR algorithm is effective in revealing intrinsic inter-subject relationships (Kyathanahally et al 2015; Yang et al 2014a) or patient subtypes (Yang et al 2014b). Supplementary Fig.…”

Functional Magnetic Resonance Imaging of the Domestic Dog: Research, Methodology, and Conceptual Issues

“…However, this approach does not take into account the facts that: (a) spin history effects and through-plane motion are not modeled in rigid-body registration or by censoring only affected TRs, (b) the frame-wise displacement of different voxels in the brain are different from each other, and (c) rapid motion that occurs between TRs can affect data quality in ways that cannot be restored by rigid-body registration or even censoring. Some of these issues were partially addressed by Jia, Pustovyy, et al (2014) and Kyathanahally et al (2015) by employing a single external infrared camera to record dogs’ head motion with high temporal resolution (order of milliseconds) and spatial precision (order of micrometers) and then correcting for those effects post hoc . However, in an ideal scenario, we suggest employing prospective motion correction by either employing an external camera (Todd, Josephs, Callaghan, Lutti, & Weiskopf, 2015; Maclaren et al, 2012) or using imagebased tracking (as in 3D PACE; Thesen, Heid, Mueller, & Schad, 2000).…”

“…Kyathanahally et al (2015) used resting state fMRI to identify whether the default mode network (DMN), found reliably in humans (Buckner, Andrews-Hanna, & Schacter, 2008) and monkeys (Mantini et al, 2011) but much less frequently in rodents (Becerra, Pendse, Chang, Bishop, & Borsook, 2011; Upadhyay et al, 2011), exists in the domestic dog. Resting state fMRI is conducted with subjects that do not perform any cognitive tasks, but rather lie still with eyes open and relax.…”

“…To assess the presence of a DMN in dogs and to understand the effects of anesthesia on its activation, Kyathanahally et al (2015) scanned six dog subjects in both awake and anesthetized states. Seed-based and independent component analyses (ICA) were used and identified dissociation between the anterior and posterior regions of the DMN.…”

Imagerie cérébrale : outils, principes et utilisations de la clinique aux sciences cognitives comparatives

“…Des études chez le chien ont également révélé un réseau un peu différent de celui de l'homme et du singe. Par exemple, les cortex cingulaires antérieur et postérieur appartiennent à deux réseaux distincts chez le chien, alors qu'ils font partie du même réseau chez l'homme ou le singe (Kyathanahally et al 2014). Chez le rat, au contraire, certaines études ont suggéré que le réseau qui associe les cortex cingulaires antérieur et postérieur est plus étendu que chez l'homme (Lu et al 2012).…”