Accepted in revised form ?????????; recieved ?????????
The objective of this study is to describe the relationship between sleeping and learning. The hippocampal neuron possesses an outstanding plastic capacity needed for learning. The so-called long-term potentiation is produced in them as a selective mechanism for strengthening the synapses activated during learning. We can objectivise this potentiation thanks to the description of the theta rhythm that appears when learning occurs. However, this rhythm also appears during sleep, so we ask, "Does a relationship between sleep and learning exist?" And if so, in which sleep phases? The existence of neuronal activation during sleep similar to that produced during learning tasks has been demonstrated both in experiments with sleep deprivation techniques and with new imaging techniques. Based on recent experiments with selective deprivation of the different sleep stages we can suggest that the processes related to memory and learning that occur during sleep begin in the deep phases of slow sleep and are consolidated during REM. The question that arises is how the different sleep phases influence the synaptic plasticity that underlies all learning processes. It has recently been demonstrated that a relationship between sleep and the neuronal growth factor exists. This means, as a final conclusion, that there is also a relationship between sleep-neurotrophic factors-brain circuits-learning.
Key Words: Learning, Sleep, Neuronal Growth Factor, Memory, Plasticity, Theta Rhythm, Long-term potentiation.
Correspondence: Jose Antonio Gil-Verona
Department of Anatomy, Faculty of Medicine
Ramon y Cajal, 7, 47005 Valladolid, SPAIN
E-mail: gil@med.uva.es