Scientists of the Institute of Science and Technology Austria found that electrochemical signals in the brain memory centers can be transmitted between neurons in the opposite direction, from Dendrita to Axon. Earlier it was believed that the transfer of impulses occurs exclusively unilaterally. A previously unknown phenomenon in the human nervous system is reported in an article published in the Nature Communications magazine.
Neurobiologists studied the interaction between the mossoid (mossy) fibers of the hippocampus from the brain and pyramidal neurons on the example of a rat brain that serves as a model organism. Between the axons of mossoid fibers and the dendrites of pyramidal cells, synaptic contacts are formed through which post-approach is carried out is the most powerful form of synaptic plasticity forming memory and training. Postedythanic potentiation enhances the excitability of pyramidal neurons (postsynaptic cells) after a short irritation of mossoid fibers (presynaptic cells).
For a long time, it was believed that post-suitantic potentiation takes unilaterally: from axon of mossoid fibers to dendrites of pyramidal neurons, that is, the synaptic plasticity corresponds exclusively to the presynaptic neurons.
The results of the new study showed that, as expected, the excitation was transferred from the nerve cells of mossoid fibers to the pyramidal neurons, but the transmission of the reverse signal was recorded: when the activity of the postsynaptic neuron increased, the synaptic plasticity decreased.
The inverse signal transmission may be provided with glutamate, which is released by dendrites and is associated with presopulptic membrane receptors. This mechanism is believed to scientists, can play an important role in optimizing the storage of information in the human brain. However, researchers still have to understand why glutamate released by signal cells does not have the same effect as glutamate postsynaptic cells.