New research suggests that the brain can become leaky at the level of the hippocampus. This means that peripheral cytokines or chemokines or inflammatory processes have the opportunity to infiltrate the hippocampus and impair signaling which ultimately can affect memory, cognition and emotions. Environmental toxins would also have the opportunity to impair normal function of the hippocampal brain region. However the plot thickens and now we learn that there are receptors in the hippocampus that influence appetite regulation that can be affected by impaired signaling. So it goes like this. High fat diets can result in a leaky more porous hippocampal area that is at risk to become infiltrated by various toxins which ultimately can create obesity as a result of poor appetite regulation and lack of satiation. Neurology Today 1-5-2012.