The molecular level of the organizational
structure of the nervous system, corresponds to the cerebral cortex, which is
organized in columns or modules of information exchange. These columns are
perpendicular to the surface of the cortex, and have approximately 3 mm in
length and between 0.5 and 1 mm wide and they are recognized as forming separate anatomical
entities that give rise to different quasi-independent functions, and even
there is research indicating that perception and memory may be distributed
through the nervous thanks to this system of organization.
In this way,
groups of cells forming vertical columns, which processed together information
from the same source of stimulation, i.e. have the same receptive field have
been described.
These
columns were established by first time in the visual cortex, but the formal
proposal of an organization in columns of the cerebral cortex, has been called
the hypothesis in Colonnade and it was formulated by Mountcastle (cited
in Arteaga and Pimienta, 2004).
However more
recent studies show the probability that other sensory areas consisting also in
columns, even proposed that the frontal lobe, to the which is credited with the
processing of the more abstract knowledge, has this kind of columnar
organization.
This
organization allows to the neocortex on the basis of a cortical hierarchy which
permitted the development of generative models of perception that gave way to
computational hierarchical models that allowed to make predictions about the
anticipation (feedforward) and feedback of the neuronal conduction including
segregation and topographic precision in both directions, whereupon it became
clear that instead of a single upper and lower chambers via of the upper and
lower areas There are bi-directional communication against the current in each
compartment of the neocortex.
In this
sense, it is speculated that these columns could be the fundamental unit of the
organization in all evolution since the columns have similar sizes and shapes,
not only within each species, but in all of them, giving the opportunity to be
plastic, which represents the maximum evolutionary invention, since it allows
the nervous system escape from the restrictions of its own genome and adapt to
the pressures both environmental as a psychophysiological changes and
experiences.
This mechanism is activated by the matching entry from
opposite poles of the neuron, which is exquisitely adapted to the final
architecture to large-scale crust and is closely controlled by neuronal
microcircuits.
All this
adds a design which in addition to creative is controversial, that allows the
sending of information contralateral (i.e. the right information is analysed in
the left side) and recently has been said this recognize and analyze the flow of energy that
is possible thanks to the response of white matter and its relationship with
the Corpus Callosum which extends the flow of information has different areas
depending on the action on the environment that required.
This
advantage is must in part to distribution patterns laminate making interaction
with different receivers required to perform different functions. In this
sense, both distribution laminar, as the relationship between areas and
receptors, creates advantages for the acquisition of learning processes, but at
the same time opens the door for various pathologies.
References:
Arteaga, G.
y Pimienta, H. (2004) Sobre la organización columnar de la corteza
cerebral Revista Colombiana de Psiquiatría. Suplemento No. 1, Vol. XXXIII.
Casper, S., Schleicher, A.,
Bacha-Trams, M., Palomero-Gallagher, N., Amunts, K., Zilles, K. (2012)
Organization of the human inferior lobule based on receptor architectonics. Cerebral Cortex. Available at: http://cercor.oxfordjournals.org/content/23/3/615.full.pdf+html
Davis, SW., Kragel, JE., Madden,
DJ., Cabeza, R. (2012) The architecture of the cross-hemispheric communication
in the aging brain: linking behaviour to functional and structural
connectivity. Cerebral Cortex. 22 (1)
232-242.
Larkum, M. (2013) A cellular
mechanism for cortical associations: an organizing principle for the cerebral
cortex. Trends in Neuroscience.
Pascual-Leone, A., Amedi, A.,
Fregni, F., Merabet, LB. (2005) The plastic human Brain cortex. Annual Review Neuroscience. 28. 377-401.
Woodrow, LS., and Dietmar, P. (2013)
The functional benefits of critically in the Cortex. The Neuroscientist. 19 (1) 88-100.
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