The anterior part of the frontal lobe, the prefrontal cortex, is the most evolved part of the brain and is responsible for positive capacities like concentration, happiness, creativity, and rational thinking. Studies using EEG have shown that meditation strengthens communication between the prefrontal cortex and other areas of the brain...
...Neurological disorders are often the result of a neurotransmitter snafu—for instance, low levels of a neuro-transmitter known as GABA are linked to depression and anxiety. Recent studies show an association between regular asana practice and increased GABA levels...Read more in Yoga International. (Thanks, +Kendall Dabaghi)