Special nerve cells in the hippocampus might be associated with time-related functions of memory.
Neurons in the hippocampus fire throughout particular minutes in time, according to research study just recently released in JNeurosci. The cells might add to memory by encoding info about the time and order of occasions.
Episodic memories include keeping in mind the “what, where, and when” of previous experiences. The “where” might be encoded by location cells in the hippocampus, which fire in reaction to particular areas. Rodents have hippocampal nerve cells that fire in reaction to particular minutes in time — the “when” — however up until just recently it was not understood if the human brain included them too.
Hippocampal nerve cells fire at succeeding minutes of a temporal period. This reveals the shooting activity of the population of time cells (N=128). Each row reveals the shooting activity for a specific time cell, balanced throughout trials. The x-axis represents time of the mean trial length. The nerve cells are arranged by the latency of the optimum shooting rate. Credit: Reddy et al., JNeurosci 2021
Reddy et al. taped the electrical activity of nerve cells in the hippocampus of epilepsy clients going through diagnostic intrusive tracking for surgical treatment. During the recording, the individuals saw and remembered a series of 5 to 7 images. At random periods, the individuals were quizzed on the next image in the series prior to it resumed. Time-delicate nerve cells fired throughout particular minutes in time in between tests, regardless of the image. The nerve cells still tracked time even throughout 10-2nd spaces without any images while the individuals waited. The scientists might translate various minutes in time based upon the activity of the whole group of nerve cells. These results show the human brain includes time-tracking nerve cells.
Reference: “Human Hippocampal Neurons Track Moments in a Sequence of Events” 28 June 2021, Journal of Neuroscience.
DOI: 10.1523/JNEUROSCI.3157-20.2021
Funding: French Agence Nationale de la Recherche, Artificial and Natural Intelligence Toulouse Institute, Fyssen structure, Université Paul Sabatier, Toulouse, France, NWO Onderzoekstalent, NWA-Startimpuls
