Final answer:
Depression and bipolar disorders are associated with changes in the amygdala, but also involve alterations in the hippocampus and the prefrontal cortex. These brain structures are part of the limbic system and are crucial for emotional processing and memory function, which are often affected in mood disorders.
Step-by-step explanation:
Depression and bipolar disorders have been linked to structural and functional abnormalities in the amygdala, but they also involve alterations in the hippocampus and the prefrontal cortex. The amygdala, a component of the limbic lobe, is crucial for emotional processing, particularly with emotions like fear and anxiety. Its interactions with various sensory areas of the brain play a significant role in classical conditioning and the emotional valuation of memories.
The hippocampus, another part of the limbic lobe, has demonstrated changes in its structure and function in relation to mood and anxiety disorders, including depression. Studies have shown that individuals with posttraumatic stress disorder (PTSD) exhibit significant reductions in hippocampal volume, which might be attributed to decreased neurogenesis and dendritic branching. Both the amygdala and the hippocampus are key to understanding how emotion and memory are processed in the brain and how these processes might differ in mood disorders like depression and bipolar disorder.
The prefrontal cortex has also been implicated, with evidence suggesting abnormal responses in this area in people with unipolar depression. The role of structures such as the cerebellum and the medulla oblongata are less clearly defined in mood disorders, thus making them less likely to be the subject of the question prompted by the student.