Panic brain pH and exercise

As this Scientific American article discusses, a recent University of Iowa study suggests that panic may be related to the brain's pH level:

In general, the pH of our brain is carefully regulated. A large increase or decrease in brain acidity can seriously disrupt brain functioning. This new study indicates that pH can sometimes rise and fall in synapses, the points of communication between individual neurons in the brain. Some synapses include specialized proteins that "sense" acidity.  These proteins (called "'acid-sensing ion channels", or ASICs) stimulate neurons when increased acid is detected.

The Iowa study shows that genetically modified mice lacking these acid-sensing proteins have a greatly reduced capacity to show either instinctive or learned fear.  When the researchers restored the ASIC gene only in the amygdala of these genetically modified mice, they observed a normalization of fear behaviors. So their studies suggest that the ability to detect changes in synaptic pH in the amygdala is essential for normal fear behavior...

The Iowa findings might help explain the significance of another curious observation: patients with panic disorder tend to generate excess lactic acid in their brains. Scientists have long hypothesized that an abnormality affecting basic cellular metabolism or pH lay at the heart of the genetic vulnerability to panic disorder.  One of the products of glucose metabolism is lactic acid, or lactate. Lactate is constantly being produced and consumed during brain activity, but if it accumulates in the brain, it will make the brain more acidic.  Recent studies have shown that patients with panic disorder consistently build up excess lactate in their brains during ordinary mental activities. The results of the Iowa studies suggest that one of the triggers for “spontaneous” panic attacks in patients with panic disorder might be lactic acid accumulating in acid-sensitive fear circuits.

As of now, there's no magic pill you can take to lower your brain's lactic acid levels. There is something you can do, though -- something we've discussed before here on PANIC!:

...one of the many beneficial effects of aerobic exercise training (like running or cycling) is that metabolically active tissues (including the brain) become more efficient at consuming -- removing -- lactic acid. There is growing evidence that exercise training has powerful anti-anxiety and anti-panic effects. This invites the speculation that exercise training may reduce anxiety in part by improving the brain's ability to prevent excess acid accumulation in acid-sensitive brain regions involved in fear. If experiments support this idea, then specific exercise training regimens could be designed to take maximum advantage of this anti-anxiety mechanism.

Now go break a sweat.