The stria terminalis, or terminal stria, is a bundle of fibers in the brain that carries messages to and from the amygdala, an area of the brain believed to be the center of emotional behavior. Beginning at the amygdala, the stria terminalis follows a path that eventually connects to the hypothalamus, a portion of the brain involved in regulating metabolism, body temperature and blood sugar. The terminal stria ends in an area of the hypothalamus' ventral medial nucleus.
As part of the ventral amygdalofugal pathway connecting the hypothalamus and the amygdala, the terminal stria and the areas it connects are associated with many human responses. Among the functions controlled by this part of the brain are motivation and the learned response of cause and effect. Through the information carried by the terminal stria, humans learn to associate consequences, both good and bad, with certain actions.
The terminal stria is also important to the septal area, which is a part of the brain associated with pleasure in humans. The septal nuclei, via the terminal stria, receive input from the hypothalamus, thalamus, amygdala and olfactory bulb, which is part of the sense of smell. Once the olfactory bulb receives a scent, the connecting pathway allows the brain to identify the scent and classify it.
Upon receiving input conveyed through the stria terminalis, the amygdala may trigger a strong emotional response. Aggression, fear and panic attacks are thought to originate in the amygdala. This part of the brain is also associated with the combined memory of emotions and events. Researchers believe this is the source of the so-called "gut feeling" many people experience; this is a reaction or belief that cannot be immediately explained through logic.
Studies conducted on the stria terminalis using animal specimens may hold information that could soon prove beneficial to humans suffering from an addiction. Disruptions or damage to the stria terminalis led to rodents returning to old behaviors to seek drugs once again. Researchers believe this part of the brain may help explain why some addicts are prone to relapse, but further studies are needed.
The bed nucleus of the stria terminalis (BNST) is believed to play an important part in how humans respond to anxiety and perceived threats. Some studies indicate that the BNST may be responsible for promoting inhibitions when interacting with strangers. Although studies are far from conclusive, one area of the BNST may play a part in gender identity.