FEATURE: DEPRESSION AND EXERCISE your brain sometimes doesn’t get • Hippocampus – known as the Over the past few years, it has been the time it deserves. ‘Emotional Brain’ has rich connections consistently reported that exercise is and the highest level of glucocorticoids good for the brain and is one of the major The brain does not finish major (neural plasticity). When the brain is strategies recommended in managing development until we are 24 years old, highly anxious and has too much depression. We know endorphins get developing from the back to the front, activity, it becomes difficult for the released from our brains that interact and completed with the prefrontal cortex hippocampus to help fight depression. with receptors in our brains and act as (PFC) which we call the ‘Smart Brain’. The hippocampus puts things into analgesics, which means they diminish space and time, so when it shrinks, the perception of pain, and also act It is also important to ensure we it cannot process these accurately. as sedatives. Endorphins trigger positive understand the difference between The hippocampus plays a major role feelings that often get described as moods and emotions, as surprisingly in sleep – with a lack of sleep making experiencing an ‘exercise high’ and few people can differentiate between the hippocampus more receptive to make us feel generally more positive the two. even the smallest stresses. It is about everything. significantly impacted by both Moods are tonic, background, and alcohol and other drugs such Amongst other research, chemicals subjective states, sustained and long- as benzodiazapines. such as serotonin, a neurotransmitter term. They are autonomous of life events that assists in the regulation of moods, and the environment and they are deep • Anterior Cingulate Cortex – helps the appetite and sleep, has also been shown in tone and self-directed. Emotions PFC to recognise and feel motivation to increase through exercise and assist are phasic changes involving psycho- and direct activity towards goals. This individuals who are suffering with physiological response systems – part of the brain plays a major role in depression, to function better. emotions are responses to events personality and is the link between and exist at a more superficial level limbic structures, orbitofrontal cortex Numerous studies over the years and are generally shorter in duration. (OFC) and PFC. The shift between have also looked into depression and cognition and emotion are important exercise to determine what is happening There are four key structural areas in for conflict resolution. in relation to molecular links between the brain that are linked with depression: exercise and resistance to depression. • Prefrontal Cortex – is responsible for Studies have indicated a 3-week training •Amygdala – plays a vital role in keeping sequencing behaviour and integrates program in humans increased muscle us safe – it scans for novelty and is motor activity and speech with sensory expression of KAT enzymes, PPAR-alpha activated by surprising, ambiguous information. It is responsible for and PPAR-beta. This suggests exercise– or uncertain situations (Domes 2007). working memory and reaches full induced changes in kynurenine The amygdala can increase in volume operation in our mid 20’s. The left metabolism could also occur in humans, within the brain when there is and right PFC have great importance and so may explain the beneficial effects hyperresponsivity to the environment. in helping us understand anxiety. of exercise in depressed patients. The amygdala learns what sensory inputs are dangerous and forms Depression and cognition have been In rodents, running has been shown associations between pain, danger, shown to significantly affect memory, to improve cognition and synaptic and negative outcomes with thoughts and emotions closely plasticity, reduce depression behaviours, linked. Depression is associated with and enhance hippocampus neurogenesis. •The hyperactivation of the amygdala a higher resting heart rate and a reduced Peripheral factors generated outside heightens anxiety readiness and heart rate variability, elevated systemic of the central nervous system during therefore increases worrying vascular resistance, elevated mean exercise are also known to affect ruminations in the brain. arterial pressure, and a variety of other neuronal function, including skeletal symptoms (Riba et al. 2012). muscle, an important source of muscle- VOLUME 36 • ISSUE 2 2018 25 retciperD/segamiytteg