Scientists have noticed that the upper and lower parts of the hippocampus are responsible for different memories.
Biologists from Boston University conducted experiments on mice, which showed that the upper and lower parts of the hippocampus are responsible for different emotional colors of memories. The work was published in the journal Current Biology.
The hippocampus is an area of the brain associated with the limbic system. She is involved in the formation of emotions and the consolidation of memory. Earlier, researchers from Uppsala University (Sweden), in collaboration with Brazilian scientists, showed that the so-called oriens lacunosum-moleculare (OLM) interneurons in the hippocampus play an important role in the learning process, and the effects on them can regulate learning success. In addition, there are cells in this area that are responsible for the perception of short periods of time. The study of its functions continues. Now scientists from the United States have demonstrated that there is a difference between the dorsal (upper) and ventral (lower) parts of the mouse hippocampus.
Applying the optogenetic technique and raising mice with luminous proteins that are activated when a neuron works, the authors set up experiments in rodents. First, they exposed animals to different stimuli: negative (weak electrical discharges), neutral and positive (courting a female). During this time, they observed which neurons were activated. Scientists noticed that in the first and last cases, different parts of the hippocampus came into operation.
To test the hypothesis, they activated the upper and lower regions of the hippocampus with light. In the latter case, a form of anxious behavior with a demonstration of fear was triggered in mice. Stimulation of the dorsal part, on the contrary, reduced the level of anxiety and anxiety. The authors suggest that different parts of the hippocampus may correlate with memories of different emotional colors. If this assumption is correct, then the activation of one or another part can suppress or strengthen memories. Boston University researchers see this discovery as a pathway to a new treatment for PTSD.
Last year, researchers at the University of California, San Diego conducted experiments with people with disabilities in the temporal lobe of the brain. They showed a link between normal hippocampal functioning and conscious memory.