Resting state functional connectivity data supports detection of cognition in the rodent brain

Abstract

Learning is a process which induces plastic changes in the synapses and connections across different regions of the brain. It is hypothesized that these new connections can be tracked with resting state functional connectivity MRI. While most of the evidence of learning-induced plasticity arises from previous human data, data from sedated rats that had undergone training for either 1 day or 5 days in a Morris Watermaze is presented. Seed points were taken from the somatosensory and visual cortices, and the hippocampal CA3 to detect connectivity changes. The data demonstrates that 5-day trained rats showed increased correlations between the hippocampal CA3 and thalamus, septum and cingulate cortex, compared to swim control or naïve animals. Seven days after the training, persistent but reorganized networks toward the cortex were observed. Data from the 1-day trained rats, on the contrary, showed connectivity similar to the swim control and less persistent. The connectivity in several regions was highly correlated with the behavioral performance in these animals. The data demonstrates that longitudinal changes following learning-induced plasticity can be detected and tracked with resting state connectivity.

Total Salvianolic Acid Balances Brain Functional Network Topology in Rat Hippocampi Overexpressing miR-30e

“…RS-fMRI has recently been highlighted as a new technique for functional connectivity changes in subjects with different subtypes of mild cognitive impairment (MCI) and different stages of cognitive impairment, which avoids variability in task fMRI ( Joo et al, 2016 ; Li et al, 2017 ; Pan et al, 2017 ). Similar findings were obtained in animal models, as resting-state functional connectivity data supports the detection of cognition in the rodent brain ( Nasrallah et al, 2016 ). These findings were mainly acquired by independent component analysis or seed-based approaches to delineate functionally connected brain regions or networks of regions.…”

“…The behavioral changes in rats have been confirmed by RS-fMRI that had a linear correlation with functional topology networks ( Nasrallah et al, 2016 ). Therefore, we chose the Y maze and MWM tasks, which are the most commonly used behavioral tests on rats’ memory performance ( D’Hooge and De Deyn, 2001 ; Kim et al, 2006 ), to explore the effects of miR-30e overexpression and TSA treatment on rat behavior.…”

Altered neural connectivity in adult female rats exposed to early life social stress

“…Previous behavioral and neuroendocrine gene expression analyses of ECSS exposed animals have described depressed maternal care, decreased aggression, increased anxiety, and numerous behaviorally relevant changes in gene expression in stress and depression associated nuclei [5,6,15]. The present approach identified functional connectivity in the range of our previous rat studies [10,11,16] and those of other groups [17,18], and was sensitive to group differences even at modest connectivity levels. These rodent RSFC data support the hypotheses that the ECSS procedure has long term effects on neural connectivity in numerous social behavior, stress, and depression relevant brain nuclei and that socially focused pathological animal models involve robust changes in resting connectivity in multiple clinically relevant networks, including the limbic system, the reward system, and the introspective socioaffective and salience networks.…”

Altered functional connectivity within the default mode network in two animal models with opposing episodic memories

“…In addition, it is reported that DMN regions are involved in a wide spectrum of language processing, visual and auditory attention, and motoric activities [ 29 ]. In animal studies, it has been shown that the connectivity within the rat DMN is increased after maze learning but decreased one week later, suggesting that the rodent DMN may be involved in early memory consolidation [ 30 ]. Other groups further identified sub-network modules in the rat DMN that display age- and behavior-related decline [ 31 ].…”