Anxiety disorders are common with one in four people diagnosed with it at least once in their lifetime. Psychological trauma can cause genetic, biochemical and morphological changes in neurons in the brain's amygdala—the region affected by stress-induced anxiety, leading to the onset of anxiety disorders such as panic attacks and post-traumatic stress disorder.
A new study by researchers at the Universities of Bristol and Exeter has found a gene in the brain that is responsible for anxious feelings. According to scientists, gene alteration decreases anxiety levels, providing a new therapeutic focus for anxiety disorders, according to the press statement by the University of Bristol. The discovery was published online in Nature Communications.
The efficacy of existing anti-anxiety drugs is low with more than half of patients not achieving remission following treatment. Limited success is linked lack of understanding of the neural circuits underlying anxiety and molecular events resulting in stress-related neuropsychiatric states, according to the statement.
This study aimed to identify the molecular events in the brain related to anxiety. The focus was on molecules, known as miRNAs in animal models. This group is also found in the human brain and regulates multiple target proteins controlling the cellular processes in the amygdala.
In this study, the team showed that increased miR483-5p, a type of molecule suppressed the expression of another gene, Pgap2, which drives changes to neuronal morphology in the brain and behaviour associated with anxiety. Hence, the study showed that miR-483-5p works as a molecular brake that balances stress-induced amygdala changes to promote relief from anxiety.
This is the first stepping stone towards the discovery of novel, much-needed treatments for anxiety disorders. Stress can lead to several neuropsychiatric conditions that rooted in an adverse combination of genetic and environmental factors "While low levels of stress are counterbalanced by the natural capacity of the brain to adjust, severe or prolonged traumatic experiences can overcome the protective mechanisms of stress resilience, leading to the development of pathological conditions such as depression or anxiety,” Dr Valentina Mosienko, one of the study's lead authors said in the statement.
The identification of pathway we identified offers a huge potential for the development of anti-anxiety therapies.