The canine brain has the same basic structure as that of other mammals, including humans. It is made up of cells called neurons, which carry and send information through a combination of electrical and chemical signals. The connectivity of different brain regions is determined by how neurons interact with one another. The human brain has approximately 85 billion neurons, whereas the smaller dog brain has somewhere around 2.2 billion neurons.
Cerebral Cortex
The wrinkly outer layer of the brain is called the cerebral cortex. It has two halves called the left and right hemispheres. The cerebral cortex is involved in many different functions, including processing sensory information, motor information, and generating cognition. When you train your dog, you are engaging with their cerebral cortex.
The two hemispheres are each made up of four large subdivisions called lobes. The occipital lobe is at the rear of the brain, and it processes visual information. In front of the occipital lobe on the top of the brain is the parietal lobe. It has several functions, including interpreting the somatosensory (touch) and proprioceptive (body position) senses. It also integrates information from different senses.
Below the parietal lobe on each side of the brain is the temporal lobe. This lobe is not only responsible for processing auditory information, but also memories and emotions. In humans, this lobe is crucial for perceiving and producing language. The canine temporal lobe is not capable of producing language, but it is involved in responding to human voices and words.
Last but not least, the frontal lobe is situated at the front of the brain. It interacts with the rest of the brain and uses information that it receives to make decisions. It is also responsible for controlling motor behavior and generating complex cognition.
Olfactory Bulb
In dogs, the olfactory bulb is the large, smooth structure at the front of the brain. Humans also have an olfactory bulb, but it is much smaller and is hidden underneath the frontal lobe. The canine olfactory bulb is 3 times larger in dogs than in humans, which may be related to their superior olfactory abilities. This structure receives information about smell directly from the nose, and helps discriminate between odors.
Midbrain
Hidden within the brain is the midbrain. It is involved in controlling eye movements and reflexes, among other things. Information from most senses reaches the midbrain first before it is processed by the cerebral cortex.
Brainstem
Below the midbrain is the brainstem, which looks like a smooth, long “tail” at the bottom of the brain. It is essential for survival, and regulates important functions like breathing and heart rate.
Cerebellum
The cerebellum is the wrinkly ball-shaped structure at the rear of the brain next to the occipital lobe of the cerebral cortex. Its name in latin translates to “little brain.” The cerebellum works closely with the cerebral cortex to modulate movement and cognition.