L-Dopa and the Fear Response

L-DopaWhat causes us to be afraid, and how can we control it? Jonathan Silver, MD gives some insight about the role of L-Dopa in the fear response. L-Dopa is the precursor to the neurotransmitter dopamine. Recent studies have shown that the production of L-Dopa may induce an effect on the resurgence of fear in humans.

Researchers further investigated this hypothesis through the use of mouse models. To cause the conditioned response of  fear, the mice were exposed to a foot shock. After the fear response ended, the mice were given a dose of L-Dopa or saline.

After being put in the conditioning cage 1,7, and 30 days later, the mice who had been given the L-Dopa preivously demonstrated less spontaneous recurrence of fear than the mice that had been given saline. The experiment on the mice sparked the curiosity of individuals about what L-Dopa’s effect on the response of fear in humans. Out of an experimental group of 60 men, the men who were exposed to the placebo showed deactivation of the left ventromedial prefrontal cortex when experiencing renewed fear. The men who received the L-Dopa did not experience the same deactivation.

The extinction of fear appears to be linked to greater levels of dopamine activity in the ventromedial prefrontal cortex.
With this newfound information about the role of L-Dopa in expelling fear, there is sure to be more research to follow in the future to help us gain a better understanding of the fear response.

For more information, you can read the full article here.