The role of synapses in the formation of a temporary connection

Process make contact and Nia temporary connection during the formation of the conditioned reflex is that previously inactive synapses neurons becomes Xia passable for nerve impulses and the combination of conditional baa of the conditioned stimuli. Initially it was thought that at the time the image of Bani reflex occurs the growth processes of nerve cells in tanavlivayuschih new intercellular communication, or the formation of peculiar outgrowths ( “spines”) on the apical dendrites feasts etc. GOVERNMENTAL neurons. However, in recent years more and more popular it is the pre d representation that during the production of the conditioned reflex changing properties existing between respective neurons sina n cos, t.   e.   It increases the efficiency of synaptic transmission at the expense item of Vyshen conductivity of existing synapses. It is assumed that as a result of the combination of the conditioned signal and the unconditioned stimulus, a mediator appears in the synapse, providing transmission of excitation (as a result of the expression of the gene controlling the synthesis of this mediator). Thus, synaptic hypothesis that morphological e skie connections between individual neurons exist prior vyrabo t ki reflex, t.   e.   they are innate, and their functioning and formation begins only in the process of forming a conditioned reflex.

Some researchers believe that the increase in the conductivity of synapses in developing conditioned reflex caused by continuous circus at lyatsiey nerve impulses between the centers of excitation in the cerebral cortex, t.   e.   on ring bark systems. Schittaetsya, the output and the m pulses per side closed circles occurs when sufficient inte n sivnosti excitation or nerve hyperexcitability e e cops this way. This degree of excitability achieved with a com and SRI conditioned and unconditioned stimuli when two pulses are merged streams. As a result, a continuous set of qi p kulyatsiya excitation of a closed ring system. This will constantly maintain the state of increased excitability and those neurons in whose synapses the temporary connection closes, t.   e.   post about Janno be maintained patency of these synapses.

Other authors have suggested that the increase in conductivity due to synaptic myelination process presynaptic terminals to about tory occurs under the influence neuroglia (mainly oligodienes d ROCIT). These changes occur in presynaptic sites ner in GOVERNMENTAL fibers which excitation caused indifferent pa of drazhitelem reaches the “inactive” ( “potential”) synapses on the bodies of neurons of cortical representation of the unconditioned reflex. Initially, these synapses are impassable for pulses because the presynaptic nerve terminal portion devoid of myelin on span of, whereby electrotonic extension of the currents in this area extends to gradual weakening and attenuated action currents cause the release into the synaptic cleft comparatively n th large number mediator insufficient to invoke the next neuron excitation. This irritation, which remains without an external effect, will cause only certain physicochemical changes (the “chemical trace”) both in the membranes of nerve endings and in the intercellular medium around them. This footprint fades out over several minutes. Proceeding from the idea that the process of myelination of nerve wave of con is a function of neuroglial cells – oligodendrocytes, env from zhayuschih neurons and their contacting surfaces, it is believed that the process of myelination occurs so that the process of oligodendrocyte and adjoins naked axons, twisting spirally around it. Mi e linizatsiya ends at a certain stage of ontogeny, however cn about lities to oligodendrocytes mielinoobrazovaniyu persists in the mature central nervous system, especially when rising stimulation ol and godendrotsitov, t.   e.   with prolonged depolarization of their membranes. This creates favorable conditions for electrotonic camshaft of roubleshooting current expiry: synapses will achieve increased current, causing a large number of photons selection mediator, sufficient to excite the next neuron and the matching p e stocks. So the temporary connection is closed, t.   e.   synapse of impenetrable ( “potential”) becomes the traversed ( “date”), and and n Trim stimulus begins to cause reaction. In the future, with the increase in the number of layers in the newly formed myelin sheath, this connection becomes more solid and perfect.

local_offerevent_note April 13, 2019

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