The flight or fight response is activated when animals face a sudden threat. During a threatening situation that presents suddenly, the sympathetic nervous system releases a number of hormones, including noradrenaline, which is essentially responsible for the increase in heart rate, blood pressure, and alertness.
Researchers believe glutamate, a neurotransmitter also plays an important role in this response. Elevated levels of glutamate have been associated with normalization of the fight or flight response and reduction of anxiety.
Male and female marmosets were studied to narrow the suspected area of the brain responsible for anxiety. Researches have located the brain circuitry accountable for the differences in anxiety seen in individual monkeys
The findings from the research suggest that increased levels of the neurotransmitter glutamate calms down the flight or fight response in monkeys.
Findings from previous studies
The role of glutamate, hippocampus and two prefrontal brain regions (area 25 and area 32) in the response to threat has been previously suggested in studies on humans and animals. However, the exact contribution of each to anxiety has not been clearly understood yet.
Hannah Clarke and other researchers from the study successfully increased glutamate release in the anterior hippocampus in order to reduce anxiety in monkeys while interacting with an unfamiliar human.
In an anxious individual, the levels of glutamate are typically found to be in the lower range, and an increase in their levels was associated with a significant reduction in anxiety. All of these effects were elicited on area 25, implicating that area 25 might be the region to target for anxiety reduction.