In part 1 of Sleep and our dogs, I explained the importance of safe, social, good quality and comfortable sleep to promote and maintain good health.
I would now like to go into a little more detail on the importance sleep plays in helping our body and brain to rebalance. Indeed. we might be tempted to think that sleep is a passive state of unconsciousness, this is however far from the truth. Sleep is a complex process of active internal restoration, recuperation and reconsolidation that is essential to our health and well-being. It is the same for our dogs.
Sleep is essential to our well being when we do not sleep we do function as well, we feel tired and irritable, we make (more) mistakes and if taken to extremes we die. It is the same with our dogs and their sleep patterns are similar to ours.
Slow Wave Sleep (NON REM Sleep) takes up +/- 70% of our dog’s sleeping time = sleep of the brain. It has 3 stages:
Stage 1: the stage between wakefulness and sleep. It is difficult to pinpoint the actual point of falling asleep as brain wave activity gradually slows down with breathing becoming more regular and the heart rate slowing down.
Stage 2: the first real stage of sleep during which muscle activity decreases further and conscious awareness of the outside world begins to fade completely. Brain waves are mainly in the theta wave range (as in stage 1 sleep), but in addition the dog experiences short bursts of brain activity (spindles) and K-complexes. Together, these help to protect sleep by suppressing response to outside stimuli, as well as aiding in sleep-based memory consolidation and information processing.
Stage 3: is also known as deep, delta or slow-wave sleep (SWS). During this period the dog will be even less responsive to the outside world and therefore pretty much unaware of any sounds or other stimuli. Both brain activity and physical indicators such as breathing rate, heart rate and blood pressure are all at their lowest levels. Information processing and memory consolidation continues to occur during this period.
REM sleep = sleep of the body
The slow wave phase is followed by the rapid eye movement phase (REM). Interestingly, there is more electrical activity in the brain when in REM sleep than when awake (this applies just as much to us humans as it does to dogs), so the dog may seem more agitated during this type of sleep. You may notice his eyes rolling and the dog may even whine or bark and move his limbs. As there is a lot of brain activity during the REM phase, there are certain theories (1) according to which dogs have dreams. Puppies will spend more time in the REM phase. During REM sleep, there is also increased activity of a specific part of the brain, which has an effect on GABA (2), which results in paralysis of the core muscles so they cannot get up but will twitch, wag their tails, whimper etc… this is why dogs must be able to lie flat out.
SWS and REM sleep promote different types of learning and REM sleep appears to promote brain development. Sleep is important to recreate homeostasis.
- Rebalancing serotonin levels
- Regulating brain electricity
- Consolidating memory
- Reducing cortisol levels
- Boosting the immune system
- Enhancing tissue repair in the brain (and the body)
- “Safe” experiencing of potential outcomes prepare the brain for future possibilities
So lets make sure that both we and our dogs get the safe, good quality and comfortable sleep we need on a regular basis.
(1) Studies have indicated that dogs have the same blood flow to the visual areas of their brain that we do, so it is very likely that they are seeing images but we will probably never know.
(2) GABA is the most inhibitory neurotransmitter in the brain and it appears to have a widespread distribution in both the brain and spinal cord. Its natural function is to reduce the activity of the neurons to which it binds. Some researchers believe that one of the purposes that GABA serves is to control the fear or anxiety experienced when neurons are overexcited
MARINA GATES FLEMING
Canine Consultant – Country Representative PDTE
00 32 (0)479 50 32 21 or email@example.com