Resume: Dogs with anxiety have stronger neural connections between the amygdala and other parts of the fear network in the brain compared to less anxious dogs.
Researchers at Ghent University in Belgium report abnormalities in functional neural networks of dogs diagnosed with anxiety.
Led by Yangfeng Xu (Gents Experimental Psychiatry Lab, GHEP; ORSAMI) and Emma Christiaen (Medical Image and Signal Processing, MEDISIP), the study shows that compared to healthy dogs, dogs with anxiety show stronger connections between the amygdala and other parts of the brain. the fear network.
Published in PLOS ONE on March 15, the findings could also help reveal how functional connections between anxiety-related brain regions are altered in human anxiety disorder cases.
Animal models of anxiety are an important tool for studying anxiety disorders, and the results could benefit both veterinary and human medicine. However, the many different aspects of anxiety cannot all be effectively studied in the same animal model.
While rodents are commonly studied, this new study takes advantage of the larger brain and larger cortex found in dogs to characterize neural networks related to fear. 25 healthy and 13 fearful dogs were volunteered by their owners and examined via non-invasive functional MRI (fMRI).
The dogs were treated in accordance with all necessary welfare guidelines so that they did not suffer any negative consequences from the study. The researchers studied the resting state of dogs with and without anxiety, compared network statistics and connectivity between groups, and determined their associations with anxiety symptoms.
Resting-state fMRI indicated that functional connections between the amygdala and other parts of the anxiety circuit, particularly the hippocampus, were stronger than normal in anxious dogs.
Within the fear circuit, network metrics, including global and local efficiency, were higher in the amygdala of fearful dogs. Dogs that showed fear and anxiety towards strangers, as well as irritability, were more likely to have brains that showed abnormal network statistics in the amygdala.
The researchers believe their findings demonstrate that resting-state fMRI is a good tool for studying canine models of anxiety, and that future studies such as this one could increase our understanding of how anxiety-related circuits in the brain are altered in animals with an anxiety disorder. and possibly even people with the condition.
The authors add: “In this manuscript, we constructed functional brain networks using graph theory statistics to compare the differences between anxious and healthy dog groups.
“Our findings may provide further insight into the topological organization of the functional brain connectome in anxiety disorders, leading to a better understanding of the pathophysiological mechanisms and disease course of anxiety in both animals and humans and aid in the development of more personalized and effective therapies. ..”
About this fear and animal psychology research news
Author: Press Office
Contact: Press Service – PLOS
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Original research: Open access.
“Network Analysis Reveals Abnormal Functional Brain Circuitry in Anxious Dogs” by Yangfeng Xu et al. PLOS ONE
Network analysis reveals abnormal functional brain circuits in anxious dogs
Anxiety is a common illness in human psychiatric disorders and has also been described as a common neuropsychiatric problem in dogs. Human neuroimaging studies showed that abnormal functional brain networks may be involved in anxiety.
In this study, we expected similar changes in network topology to be present in dogs as well. We performed resting functional MRI in 25 healthy dogs and 13 patients.
The generic Canine Behavioral Assessment & Research Questionnaire was used to evaluate anxiety symptoms. We constructed functional brain networks and used graph theory to compare the differences between two groups. No significant differences were found in the global network topology.
However, focusing on the fear circuit, global efficiency and local efficiency were significantly higher, and the characteristic path length was significantly lower in the amygdala in patients.
We found higher connectivity between amygdala hippocampus, amygdala mesencephalon, amygdala thalamus, frontal lobe hippocampus, frontal lobe thalamus, and hippocampal thalamus, all part of the fear circuit. In addition, correlations between network statistics and anxiety symptoms were significant.
Altered network measurements in the amygdala were correlated with stranger-directed anxiety and irritability; altered grade in the hippocampus was related to attachment/attention seeking, trainability, and touch sensitivity; abnormal frontal lobe function was related to hunting and known canine aggression; attachment/attention-seeking was correlated with functional connectivity between amygdala-hippocampus and amygdala-thalamus; known canine aggression was related to the change of global network topology.
These findings may shed light on the aberrant topological organization of functional brain networks underlying anxiety in dogs.