Canine brain networks have provided valuable insights into the evolution of mammalian brains. Researchers have discovered that the lateral frontal lobes, responsible for problem-solving, task-switching, and goal-directed behavior, have partially taken over the role of the cingulate cortex, a bilateral structure deep in the cerebral cortex. To better understand how dogs think, scientists have employed functional magnetic resonance imaging (fMRI) to observe their brain activity in response to external stimuli. By analyzing the active regions of the brain during these reactions, researchers can gain a deeper understanding of the cognitive processes involved in learning, memory, and the development of human brain function.
The Department of Ethology at Eötvös Loránd University (ELTE) has been instrumental in advancing the methodology for canine fMRI measurements since 2006. Márta Gácsi, a prominent figure in the field, developed a training methodology for pet dogs that incorporated principles from assistance dog training in Hungary. By combining these approaches with socially motivated training and ethological research, Gácsi devised a highly effective method. In this approach, dogs are motivated to learn tasks by observing the actions of already trained dogs and receiving praise. Through fMRI training, dogs can remain motionless in the MRI scanner for extended periods, typically around eight minutes, in exchange for expected rewards such as petting and treats.
In recent years, canine fMRI studies have focused on playing sounds to the animals and examining the brain regions activated during sound processing. However, one challenge researchers face is the irregularity of functional activities, which do not necessarily adhere to anatomically defined boundaries. Different parts of the brain often work together in synchrony to process specific inputs, forming functional brain networks. To address this issue, the researchers decided to develop a dog brain atlas that organizes anatomical regions into functional networks. This atlas illustrates which regions are involved in specific tasks and provides information about their locations. The study detailing this approach was published in the journal Brain Structure and Function.
The creation of a canine resting state fMRI brain atlas has significant implications for the analysis of brain disorders characterized by impaired integration and communication between different brain areas. By mapping the functional networks in the dog brain, researchers can gain a better understanding of these diseases and potentially develop improved treatment strategies. Moreover, the insights obtained from studying canine brain activity not only contribute to advancements in dog training methods but also shed light on the evolutionary processes that led to the development of human brain functions.
New atlas for dog brain researchers
The construction of the functional brain atlas involved the participation of 33 trained pet dogs. During the fMRI recordings, the dogs were simply instructed to remain still in the scanner, without engaging in any specific tasks or focusing on anything in particular. This type of fMRI, known as resting-state fMRI or rs-fMRI, allows researchers to investigate brain activity while the subject is in a relaxed and inactive state. By analyzing the data collected during this resting state, researchers can uncover functional relationships and connections between different brain regions, thus exploring brain networks.
To enhance the original methodology, network theory was applied in collaboration with Milan Janosov, a data scientist specializing in network analysis at Central European University. Previous studies primarily described model-based networks without considering anatomical boundaries. However, the development of new canine MRI brain atlases, which accurately represent anatomical regions at the required resolution, enabled researchers to examine the strength of connections within networks and between networks. Additionally, the large number of dogs involved in the study facilitated comparisons across species.
This novel approach not only provides a comprehensive understanding of the functional brain networks in dogs but also allows for valuable comparative studies between species. By employing canine fMRI and network theory, researchers are gaining deeper insights into the intricate connections within the canine brain, paving the way for advancements in neuroscience and contributing to our understanding of brain function in both dogs and humans.
Brains dominated by different areas in dogs and humans
The study reveals that in dogs, the networks responsible for problem-solving, task-switching, and goal-directed behavior—located in the lateral frontal lobe (frontoparietal)—play a lesser role compared to humans. Instead, the cingulate cortex, a bilateral structure deep within the cerebral cortex, takes on a central role in canine brain function. This region is involved in various essential processes, including reward processing and emotion regulation. Interestingly, the cingulate cortex in dogs is relatively larger compared to its counterpart in humans. These findings highlight the distinct neural organization and functional specialization in dogs, indicating that the cingulate cortex assumes a prominent position in cognitive and emotional processing within the canine brain.
The effects of aging
The study involved the measurement of dogs across different age groups, including the oldest participant who was 14 years old. Ensuring accurate measurements required the dogs to remain motionless during the fMRI scans.
Analysis of the data revealed a slight decrease in the ability of older dogs to maintain their initial position. However, this difference was minimal, with head displacement measuring less than 0.4 mm. This observation parallels findings in humans, as older individuals also experience greater difficulty in maintaining stillness for prolonged periods compared to their younger counterparts. Eniko Kubinyi, a senior researcher specializing in cognitive aging in dogs, highlighted this similarity.
This study offers valuable insights into the evolutionary trajectory of the human brain. It suggests that during the evolution of mammalian brains, the cingulate cortex's role was partially assumed by the frontoparietal regions. Furthermore, the newly developed rs-fMRI brain atlas holds great potential for investigating conditions characterized by impaired integration and communication between brain regions, leading to disrupted task allocation. Aging, anxiety, and psychiatric disorders represent some examples of such conditions where this atlas can provide valuable insights.
Source: Eötvös Loránd University