Structural connectome alterations in anxious dogs: a DTI-based study

Anxiety and fear are dysfunctional behaviors commonly observed in domesticated dogs. Although dogs and humans share psychopathological similarities, little is known about how dysfunctional fear behaviors are represented in brain networks in dogs diagnosed with anxiety disorders. A combination of diffusion tensor imaging (DTI) and graph theory was used to investigate the underlying structural connections of dysfunctional anxiety in anxious dogs and compared with healthy dogs with normal behavior. The degree of anxiety was assessed using the Canine Behavioral Assessment & Research Questionnaire (C-BARQ), a widely used, validated questionnaire for abnormal behaviors in dogs. Anxious dogs showed significantly decreased clustering coefficient (C-p), decreased global efficiency (E-glob), and increased small-worldness (s) when compared with healthy dogs. The nodal parameters that differed between the anxious dogs and healthy dogs were mainly located in the posterior part of the brain, including the occipital lobe, posterior cingulate gyrus, hippocampus, mesencephalon, and cerebellum. Furthermore, the nodal degree (K-i) of the left cerebellum was significantly negatively correlated with excitability in the C-BARQ of anxious dogs. These findings could contribute to the understanding of a disrupted brain structural connectome underlying the pathological mechanisms of anxiety-related disorders in dogs.

Automated summary

Anxiety and fear are dysfunctional behaviors commonly observed in domesticated dogs. This study used diffusion tensor imaging (DTI) and graph theory to investigate how dysfunctional fear behaviors are represented in brain networks of anxious dogs. Anxious dogs showed decreased clustering coefficient, decreased global efficiency, and increased small-worldness compared to healthy dogs. The nodes that differed between anxious and healthy dogs were mainly located in the posterior part of the brain, including the occipital lobe, posterior cingulate gyrus, hippocampus, mesencephalon, and cerebellum. The left cerebellum's nodal degree was negatively correlated with excitability in anxious dogs. These findings contribute to understanding the disrupted brain structural connectome underlying anxiety-related disorders in dogs.