Question

What are the functional implications of the significantly reduced volume of the (1) ventral medial portion of the prefrontal cortex and (2) hippocampus in individuals with Post-Traumatic Stress Disorder?

Answer 1

A person is said to be suffering from Post-traumatic stress disorder (PTSD) when mental health is affected after witnessing or experiencing a horrible or violent act. It creates a psychiatric disorder and the person suffers from anxiety, depression, flashbacks, nightmare, and uncontrollable thoughts about the event.

The person suffering from PTSD will suffer from 1.sleep difficulty, 2. Anger, irritated, and difficulty in controlling emotions.4. Numbness, and disconnection, 5. Feeling unsafe, 6. Thought of suicide, 7.Chronic anxiety and depression.

The researchers have concluded the amygdala, ventromedial prefrontal cortex (vmPFC) and the hippocampus are affected in the brain region.

The ventromedial prefrontal cortex is a part of the prefrontal cortex, located in the frontal lobe at the bottom of the cerebral hemisphere.

The main function of this part is to respond in the cases of fear and risk felt by the person. It plays a role in decision making and the inhibition of emotional responses and regulation.

In the persons suffering from PTSD, it is observed that vmPFC is altered during fear acquisition and is found to be an augmented level of fear that was paired previously with the shock of witnessing/experiencing violence.

As these changes are present at the first exposure to threat the person gets conditioned. The manipulation and altered vmPFC can alter the range of anxious behavior thus creating fear and anxiety after exposure to threat or violence it helps in regulating the fear and does not help in the extinction of fear as it was believed earlier.

The hippocampus is present in the inner (medial) region of the temporal lobe. The hippocampus together with the prefrontal cortex plays an important role in froming the episodic memory.

The researchers have suggested that those who suffer from PTSD have smaller hippocampi5

As Hippocampus and vmPFC are responsible for episodic memory the person who experience or witness violence find difficulty in recalling memory some part of the event will be vividly recalled and it remains present, and the other part may not be recalled in the same manner.

When a person experiences or witness violence or threat the cortisol the fear hormones is released in the bloodstream that mediates the stress when the level of cortisol is increased it damages the hippocampus Cell.

The studies have proved that those who have smaller hippocampus are more vulnerable to PTSD.

The study is going on to find out the exact role of the vmPFC and Hippocampus with PTSD.