Cognition is the most complex operation of the nervous system that allows the animals and humans to learn, form long-lasting memories, and think. Some of these memories represent environments that the animal or human explored during life. Remarkably, it was discovered in the early seventies that there are some special neurons in the rat brain, which transmit electrical signals only when the animal encounters particular locations in the environment. These neurons were named as "place cells", as their most likely function is, obviously, to process information on places. Two fundamental problems, however, have remained unresolved in the thirty-year history of these special cognitive neurons. First, it is completely unknown whether place cells in primates, such as monkeys or humans, transmit electrical signals in the same way as the place cells of lower order animals, like rats. Second, it is still unclear whether place cells process information on places only during the period when the animal or human encounters these locations, or place cells also help to form long-lasting memories on the environment. The present project will solve these problems with a new methodology, which allows, for the first time, to monitor the electrical signals of each place cell for as long as a full day, in both rats and monkeys, while the animals explore and learn the inner structure of the same, large test chamber. These studies are driven by the hypotheses that monkey place cells transmit more complex electrical signals than rat place cells, and that place cells play a key role in the formation of memories on the environment. If these hypotheses will turn out to be correct, the proposed studies will prove that the astonishing cognitive abilities of primates are due not only to the extremely large cellular mass and connectivity of their cerebral cortex, but also to the uniquely sophisticated operation of its constituent, memory-forming neurons, such as place cells. This information should provide the scientific community and the general public with a new insight into the secrets of the unparalleled processing power of the primate cognitive system: the very mechanisms that allowed the ascent of primates from the rest of the animal kingdom. These studies will afford opportunities for undergraduate students to gain first -hand experience in using non-human primates as a research model for determining neural processes regulating complex learning and memory .
