Answer. Hypothalamus is the region of the forebrain, which is located below the thalamus. It forms the basal portion of the diencephalon. The main function of it is to regulate body temperature, some metabolic processes and governing the autonomic nervous system.And the hippocampus is the part of the brain that is located inside the temporal lobe, it mainly consists of grey matter which is the component of the limbic system. The hippocampus meaning is a seahorse, as its shape is similar to that, the hippocampus plays an important role in memory and emotion.