These experiments seem to me distinctly to prove that the connection between the elements of the peripheral organ and the proximate neurone is more than one of contact.
The neurone of the third order, which terminates in the optic lobes of the brain by means of its neuraxons (the optic nerve).
The neurone of the second order, which terminates in the 'neuropil' of the second ganglion (ganglion of the optic nerve).
An alternative hypothesis is that the information resides in its ultimate form in some more central structure of the neurone than the synapse.
Thus, it would appear that the change in the base ratio of the RNA synthesized is not due to increased neurone function per se, but is more directly related to the learning process.
This is a two-neurone , but often there is a third, neurone between the and the .
Communication from one neurone to another occurs across a called the synapse.
The neurone is the of which the nervous is composed.
The Synapse Now let us consider the mode of connection between one neuroneand another in a nerve center.
Each neurone in the diagram represents hundreds in the brain, for brain activities are carried on by companies and regiments of neurones.
As soon as a neurone is stimulated at one end, it communicates its excitement, by means of the nervous current, to the next neurone or to neighboring neurones.
Just as an electric current might pass along one wire, thence to another, and along it to a third, so the nervous current passes from neurone to neurone.
This point of connection is called the synapse and although we do not understand its exact nature, it may well be pictured as a valve that governs the passage of the nervous current from neurone to neurone.
In the pathway which it traverses it leaves its impression, and, thereafter, when the first neurone is excited, the nervous current tends to take the same pathway and to end in the same movement.
With increased use they become more and more permeable, and thus learning is the process of making easier the passage of the nervous current from one neurone to another.
It is important to note that neurones never act singly; they always act in groups, the nervous current passing from neurone to neurone.
In them one neurone continues the line of conduction where the immediately foregoing neurone left it.
This is the clearest instance we have of a neurone being actually excited under natural circumstances by an agent of the environment directly, not indirectly.
The cortical neurone therefore collects impulses in the region of cortex just about its perikaryon and discharges them to other regions, some not cortical or even cerebral, but spinal, &c.
The place of juxtaposition of the end of one neuroneagainst the beginning of another is called the synapse.
Each neurone is an elongated cell which transmits nerve-impulses from its one end to its other, without so far as is known modifying the impulses in transit, unless in that part of the nerve-cell where the nucleus lies.
The neurone conductors in the cortex are in so far considered to resemble those of reflex centres, though their reactions are more variable and complex than in the use of the spinal.
They are supposed to be due to a change at the synapses connecting neurone with neurone in the grey matter.
In the dog, an animal with high olfactory sense, the axone of each olfactory neurone is connected with five or six mitral cells.
At it the conduction which has so far been wholly intra-neuronic is replaced by an inter-neuronic process, in which the nerve impulse passes from one neurone to the next.
The process there, it is natural to think, must be physiologically different from that conductive process that serves for transmission merely within the neurone itself.
The essential differences in the effects of destructive lesions of upper and lower neurones may be indicated thus:-- Upper Neurone Lesion.
When the trunk of the nerve is implicated between the pontine nucleus and its peripheral distribution, the paralysis is of the lower neurone (peripheral) type, the muscles on the same side as the lesion being flaccid and atrophied.
The paralysis of the arms is of the lower neurone type, and the muscles are flaccid and undergo atrophy; the legs may exhibit a more complete degree of paralysis of the upper neurone type, with exaggeration of the knee-jerks.
The nervous system is composed of a multitude of units, called neurones, each neurone consisting of a nucleated cell, with branching protoplasmic processes or dendrites and one axis-cylinder or axon.
When the fibres of the nerve are implicated in any part of their course between the cortical centre and the nucleus in the lower part of the pons, the paralysis is of the upper neurone (cerebral) type.
A lesion of the crus may in like manner produce spastic hemiplegia and hemianæsthesia of the opposite side, often associated with a lower neuroneparalysis of the third and fourth nerves of the same side (crossed paralysis).
Physiologically stated, free attention is given when a neurone series which is ready to act is called into activity.
So far as permanence goes, connections between sensorimotor neurone groups seem to hold modifications longer than do connections between either associative-motor or associative-association.
Forced attention is necessary when the neurone tracts used by the attention are for some reason unready to act.
The neurone groups controlling the reflex and physiological operations are least easily modified, while those controlling the higher mental processes are most easily modified.
The plasticity of neurone groups seems to vary in two respects--as to modifiability and as to power to hold modifications.
The word synapses, meaning clasping together, is used as a descriptive term for the connections that exist between neurone and neurone.
But if this same fact may be approached from several different angles by means of several chains of associations, the combined power of the activity in the several neurone chains will likely be enough to lift it above the threshold of recall.
The neurone groups controlling the instincts hold a middle place.
The difference between the three activities is a subjective matter--a difference largely in mood, in attitude of the person concerned, due to the readiness or unreadiness of the neurone tracts exercised.
The general laws of learning emphasize the importance of the mind's set as a condition to readiness of neurone tracts.
At the beginning of the modification of the neurone tract focal attention is often necessary, but as it progresses less and less attention is needed until the activity becomes automatic, apparently running by itself.
It uses neurone tracts that are not "ready" and at the same time prevents the action of tracts that are "ready.
Association is the result of habit working inneurone groups.
In different phrasing we may say: (1) Neuronegroups accustomed to acting together have the tendency to work in unison.
Your neuronegroups are accustomed to act in this way, so the sequence follows.
A neurone is a protoplasmic cell, with its outgrowing fibers.
Thus we have seen that the two parts of the neurone probably perform different functions, the cells generating energy and the fibers transmitting it.
The neurone fibers are of two kinds, dendrites and axons.
Thus it is seen that the neurone is, in its development as in its work, a unit.
It will help in understanding the peripheral system to remember that a nerve consists of a bundle of neurone fibers each wrapped in its medullary sheath and sheath of Schwann.
The cell part of the neurone is of a variety of shapes, triangular, pyramidal, cylindrical, and irregular.
This is but a technical statement of the simple fact that nerve currents flow most easily over the neurone connections that they have already used.
The Tropile-pulse sped through the neurone guides of the Pyramid net, and what it encountered it mastered, and what it mastered it changed.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "neurone" in a variety of sentences. We hope that you will now be able to make sentences using this word.
