Time Cells: Continuous Counting
The famous physicist John Wheeler, the author of the term "black holes", called the time "by the fact that he does not give everything to happen at the same time". And although it is extremely difficult to give a strict definition of time, this concept is easily accessible at an intuitive level – approximately as a consistent organization of the chain of personal experience events. Links of this "chain" can be divided by temporary intervals – and, these gaps between the events are counted by the neurons of the hippocampus.
Hippocampus is one of the most ancient areas of the brain, playing a key role in the orientation in space. The main mass of its cells is t.N. Places neurons (or spatial neurons), which are activated at the moment when a person or animal detects itself in a certain place. The activation scheme (pattern) of this group of neurons helps to form a cognitive map of the surrounding space. The important role of hippocampus in the work of memory mechanisms is also known; It is assumed that it provides encoding information for subsequent long-term storage in other brain departments (read this: "Sine-green fear"). In this regard, experts expressed the assumption of the presence of special "time neurons", which allow the consistent organization of the memorized events.
To verify this hypothesis, a team of Professor Howard Eikenbaum (Howard Eichenbaum) put a witty experiment using laboratory animals. The experience consisted of performing a rat of two tasks, separated by a delay in time – and with a parallel entry of the activity of hippocampal neurons using electrodes implanted into it. More precisely, the first task was to remember the connection between the object and the characteristic, bright odor (for example, the ball with the smell of oregano, or a cube – with cinnamon). Only then began, actually experiment. In the first chamber, the object was presented an object, then it moved for 10 seconds to the adjacent chamber, and then to the third, where there was a sand tank, sprinkled by the corresponding aroma. The rat was trained that if the object in the first chamber and the smell in the third corresponds to one of the most familiar pair ligaments, then the sand is planted – a delicious reward is waiting for it under it. If the pair did not coincide, it was useless to dig. (In the case when the rat acted correctly, she was rewarded with the ability to go through all three steps again and get food, but not – sitting off.)