Research reveals where memory fragments are stored
This separation ensures that, in the future, exposure to any individual cues is sufficient to activate the prefrontal cortex, which will then access the hippocampus to recall the entire memory.
Studying memory as a distributed brain process has been challenging, in part due to technical limitations. Priya Rajasethupathy, a neuroscientist at Rockefeller University, and her colleagues have developed new techniques to simultaneously record and manipulate neural activity from multiple brain regions as mice navigate experiences. multi-sensory experience, encountering various sights, sounds, and smells while in an endless corridor in virtual reality.
The researchers trained the rats to associate different rooms, including different combinations of sensory cues, such as rewarding or hostile experiences. Then, spurred on by a particular scent or sound, the mice were able to recall the experience more broadly and know whether to happily expect sugar water or look out for an unpleasant stream of air.
How memories are stored
Experiments have demonstrated that while the hippocampus-gut pathway, a well-studied circuit involving the hippocampus and its surroundings, is essential for the formation and storage of experiences, individual sensory features are transferred to prefrontal neurons. Then, when the mice encountered specific sensory features, another circuit came into play. This time, prefrontal neurons communicate with the hippocampus to evoke relevant global memories.
Nakul Yadav, first author of the study and a graduate student at Weill Cornell University School of Medical Sciences, said: “He was mentored by Dr. Rajasethupathy and Dr. Conor Liston, associate professor of psychiatry and science. neurologist at the Feil Family Mind and Brain Research Institute at Weill Cornell Medicine.
The findings have implications for the treatment of conditions such as Alzheimer’s disease, where the deficiency is thought to be related to recall rather than storage capacity. Dr Rajasethupathy said the existence of distinct storage and retrieval pathways in the brain suggests that targeting prefrontal recall pathways may be more promising therapeutically.