Exercise and Learning

As I go through my coursework, I’ll post assimilations of my reading material. Here comes one now!

From Adria.Richards' Flickr Photostream

One of the books I’m reading is Spark which is about exercise and its effects on the brain. Exercise does some amazing stuff for the old noodle, but I’m going to focus on just  the aspect of learning for now.

Big stuff appears to happen in the hippocampus, known to play a major role in long-term memory and learning. Basically, exercise causes your body to produce everything necessary to prepare you to learn something.

Learning happens via a mechanism called long-term potentiation (LTP). One neuron fires, sending glutamate (the most common activating neurotransmitter) across the synapse where it clicks into receptors on a dendrite (the receiving side of a neuron). If the neuron fires again, the genes of the receiving cell will start producing more building materials to prepare for locking in the memory. (Hence, firing and wiring together.)

Four Factors
Exercise causes more production of a particular protein called brain-derived neurotrophic factor (BDNF). BDNF causes your neurons to branch out, creating more dendrites and synapses (places for other cells to connect to). It also binds with receptors at the synapse, increasing the flow of ions, allowing for a stronger signal.

BDNF also helps increase the uptake of IGF-1 (insulin growth factor), which helps glucose (fuel) get to cells. It also activates neurons to produce signaling neurotransmitters (serotonin and glutamate) and spurs more production of BDNF to strengthen the structure of neuronal connections.

Your cells also need oxygen, which gets mixed with the glucose to create energy (or ATP). During exercise, when oxygen can be depleted, your body produces vascular endothelial growth factor (VEGF) to produce new capillaries in the body and brain.

Fibroblast growth factor (FGF-2) helps tissue grow, and in the brain, it’s important to LTP (the process of solidifying connections).

Basically, these factors play roles in getting fuel to neurons and help them strengthen and grow.

Neurogenesis
There are also some studies that indicate that exercising causes production of spanking new neurons. Fred Gage of the Salk Instite, along with Peter Eriksson of Sweden showed that rodents who ran on a wheel saw an increase in the number of cells that were born. In studies of chickadees that learned new songs in the spring, a significant number of new cells in the hippocampus, showing a relationship between cell growth and learning. Henrieeta van Praag showed a direct link in learning through a study in which active mice and non-active mice were shown their escape route in an opaque pool of water, then put in a second time. Both groups swam at the same rate, but the active mice more quickly found their way out, indicating that they had more effectively learned where their exit was from the previous swim.

So exercise helps to make new cells as well as shore-up and grow the old ones. However, cells have about 28 days to find something to do by joining a network, or they die off (use it or lose it). It’s a good thing that BDNF caused more dendrites to sprout – this offers more opportunity for the new cells to connect.

One other interesting tid bit is that the more complex the motor skills involved, the more BDNF in the cerebellum (involved in motor activity). Even though these circuits are created through movement, they can be used for thinking as well – which may be why learning the piano is makes it easier to learn math.

“If we’re not moving, there’s no reason to learn anything”(p. 53).

Ratey, J. R., & Hagerman, E. (2008) Spark: The Revolutionary New Science of Exercise and the Brain. New York, NY: Little, Brown & Company.