Dog Discoveries

I Am Your Dog’s Hippocampus

 

Among the many structures of the dog’s brain, the hippocampus plays several important roles. If your dog sits when you ask him to or he comes running to you when he hears you calling him, you must thank this tiny organ which stores tons of long-term memories. This structure also helps your dog navigate so he can find his way through the doggy door and it helps your dog form emotional reactions along with several other important cognitive functions. So today, let’s discover more about a dog’s hippocampus by listening to his story.

dog hippocampusIntroducing Your Dog’s Hippocampus

Hello, it’s your dog’s hippocampus talking! Yes, I am tiny, but don’t underestimate me based on size, I do a whole lot! My name derives from the Greek word “hippo,” which means horse and “kampos” which means sea. Put those two words together and you get “seahorse.” I am called this way because people think I am shaped like a sea horse, do you notice any resemblance in the picture on the right?

I am part of the limbic system and am surrounded by important neighbors such as the amygdala and the pineal gland.  People often think of me as a single structure, but in reality I am found in the left and right sides of your dog’s brain. Like other brain structures, I am known for being quite plastic.  I am just like a muscle, enlarging when used and shrinking when not in use.

”  It may even be possible to assess training efficacy by seeing how large the hippocampus becomes after a few weeks of the right type of training or how severely affected fear centers are when punitive training is employed (there is already evidence that even mild/unpleasant electric shock has long lasting (like forever) detrimental effects on these centers in rodents .  ” ~Dr. Nicholas Dodman

I Form Memoriesdog sit

When an event takes place in your dog’s life, his brain determines whether information about this event is worthy of saving. If the brain determines that the information is important, it will be saved in your dog’s “memory storage files.” I therefore play an important role when it comes to the consolidation of information from short-term memory to long-term memory. Yes, feel free to call me the storage and reception area for your dog’s memories!

Did you know? According to a study, it takes about 3 to 4 years for London taxi drivers to memorize all the route maps of the city. When the brains of these taxi drivers were scanned with an MRI, their memory center, the hippocampus, showed an increase in size. When the taxi drivers though retired, the hippocampus then shrunk back to its normal size.

dog fearI Encode Contexts

Since I often store memories that are important for survival purposes, when your dog is exposed to something that he has associated with a traumatic event, I encode such context and send an alert to my neighbor, the amygdala, the critical initiator of fear, which responds to threats triggering the dog to react. When the amygdala and I work together, through our teamwork, we can identify threatening contexts and “flag them” while discarding those contexts that aren’t threatening.

“One of the jobs of the hippocampus is to encode contexts. Those London cab drivers with oversized hippocampuses have countless contexts encoded to represent many different locations around London. The hippocampus of the puppy who had a tough time at playgroup encoded the room where playgroup happened as a context.” ~Jessica Perry Hekman, DVM, MS

I Help With Navigation dog navigation

If your dog knows how to navigate through your home, it’s thanks to me too. I help with spatial memory and navigation. Interestingly, according to data collected from Brian Hare and Vanessa Woods at Duke University, male and female dogs employed different navigational skills when it came to finding food hidden under a bowl. Female dogs were found to be more successful by using their hippocampus in what’s known as :”allocentric navigation“a  landmark-based strategy similar to forming a mental map; whereas, male dogs were found to use their basal ganglia in what’s known as “egocentric navigation.”

When Things go Wrong

I am a structure that may suffer the effects from aging. When dogs develop Canine Cognitive Dysfunction as they age, I am known to deteriorate and shrink, possibly playing a role when dogs start to forget important things such as learned obedience behaviors or how to navigate through the house to reach the doggy door. As it happens with humans, the more extensive the atrophy, the more pronounced the cognitive deficits. (Tapp et al., 2004a; Rofina et al., 2006).

I also can be damaged by certain medical conditions and I also can suffer from the effect of stress. According to veterinary behaviorist Karen Overall, stress increases cortisol and cortisol adversely affects my plasticity and my ability to learn. Medications meant to reduce stress, can take the edge off and help dogs gain back their ability to cognitively function.

As seen, I do a whole lot! The famous saying “If you don’t use it you lose it” can apply to me since I increase or shrink accordingly based on how much I am used. So keep your dog health, happy and mentally stimulated!

Best regards,

Your dog’s hippocampusDog Pawprint

 

References:

  • Dog Star Daily, “Inside a dog’s brain it’s too dark to read” … no more., Dr. Nicholas H. Dodman, retrieved from the web on August 29th, 2016
  • Current Biology, Acquiring “the Knowledge” of London’s Layout Drives Structural Brain Changes, Katherine Woollet, Eleanor A. Maguire,Volume 21, Issue 24, p2109–2114, 20 December 2011
  • Tapp, P. D., Siwak, C. T., Head, E., Cotman, C. W., Murphey, H., Muggenburg, B. A., et al. (2004b). Concept abstraction in the aging dog: development of a protocol using successive discrimination and size concept tasks. Behav. Brain Res. 153, 199–210. doi: 10.1016/j.bbr.2003.12.003
  • Rofina, J. E., van Ederen, A. M., Toussaint, M. J., Secreve, M., van der Spek, A., van der Meer, I., et al. (2006). Cognitive disturbances in old dogs suffering from the canine counterpart of Alzheimer’s disease. Brain Res. 1069, 216–226. doi: 10.1016/j.brainres.2005.11.021
  • Live Science, Female Dogs Are Better Navigators, By Brian Hare and Vanessa Woods, Duke University, 

Photo Credits:

The human hippocampus and fornix compared with a seahorse (preparation by László Seress in 1980), Hippocampus_and_seahorse.JPG: Professor Laszlo Seress derivative work: Anthonyhcole (talk) Hippocampus_and_seahorse.JPG, CC BY-SA 3.0

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