title: Default-mode-like network activation in awake rodents.
abstract: During wakefulness and in absence of performing tasks or sensory processing, the default-mode network (DMN), an intrinsic central nervous system (CNS) network, is in an active state. Non-human primate and human CNS imaging studies have identified the DMN in these two species. Clinical imaging studies have shown that the pattern of activity within the DMN is often modulated in various disease states (e.g., Alzheimer's, schizophrenia or chronic pain). However, whether the DMN exists in awake rodents has not been characterized. The current data provides evidence that awake rodents also possess 'DMN-like' functional connectivity, but only subsequent to habituation to what is initially a novel magnetic resonance imaging (MRI) environment as well as physical restraint. Specifically, the habituation process spanned across four separate scanning sessions (Day 2, 4, 6 and 8). At Day 8, significant (p<0.05) functional connectivity was observed amongst structures such as the anterior cingulate (seed region), retrosplenial, parietal, and hippocampal cortices. Prior to habituation (Day 2), functional connectivity was only detected (p<0.05) amongst CNS structures known to mediate anxiety (i.e., anterior cingulate (seed region), posterior hypothalamic area, amygdala and parabracial nucleus). In relating functional connectivity between cingulate-default-mode and cingulate-anxiety structures across Days 2-8, a significant inverse relationship (r = -0.65, p = 0.0004) was observed between these two functional interactions such that increased cingulate-DMN connectivity corresponded to decreased cingulate anxiety network connectivity. This investigation demonstrates that the cingulate is an important component of both the rodent DMN-like and anxiety networks.
authors: Translational Sciences, Advanced Technology, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois, United States of America. jaymin.upadhyay@abbott.com
authors: Jaymin
authors: J
authors: Upadhyay
authors: Scott J
authors: SJ
authors: Baker
authors: Prasant
authors: P
authors: Chandran
authors: Loan
authors: L
authors: Miller
authors: Younglim
authors: Y
authors: Lee
authors: Gerard J
authors: GJ
authors: Marek
authors: Unal
authors: U
authors: Sakoglu
authors: Chih-Liang
authors: CL
authors: Chin
authors: Feng
authors: F
authors: Luo
authors: Gerard B
authors: GB
authors: Fox
authors: Mark
authors: M
authors: Day
mesh_terms: D000818:Animals; D001007:Anxiety / Q000503:physiopathology; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping; D006179:Gyrus Cinguli / Q000033:anatomy & histology / Q000502:physiology; D007031:Hypothalamus / Q000033:anatomy & histology / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008959:Models, Neurological; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology*; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D056152:Respiratory Rate / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*