evolution of neocortex

Type of paperEssay (Any Type)

SubjectPsychology

Number of pages10

Format of citationOther

Number of cited resources4

Type of serviceWriting

should be based off of rough draft using the papers i have cited on the rough draft. needs to be a 10 page paper double spaced size 12 point font with line numbers and page numbers in scientific citation style. title, abstract, subtopics and conclusion must be included. reference page at end not included in page limit.

Additional Service

i

1-page abstract

An abstract is a paragraph (150-300 words) that summarizes the main aspects of the paper in a prescribed sequence that includes 1) the overall purpose of the study and the research problem(s) you investigated; 2) the basic design of the study; 3) major findings or trends found as a result of your analysis; and, 4) a brief summary of your interpretations and conclusions.
1

Evolution of the Neocortex

Sources

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2913577/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3610574/

Abstract

The evolution of the neocortex is widespread across many species. There is little modern research done to investigate how much the neocortex differs in terms of size, shape, and number of neurons between other species and us humans. Some studies focus on how the gyrated human neocortex evolved, through a lineage of neural stem and transit-amplifying cells that grew to form the outer sub ventricular zone. Other studies focus on the aspects of the evolution of the neocortex that make the humans novel.

Introduction

The neocortex is the part of the brain that involves sight and hearing in mammals

2

It is the most recently evolved part of the cortex and is an important component in terms of higher level cognitive functioning

origin of neocortex can be traced to reptiles that have emerged during the Carboniferous Period, where first appeared as uniform 6 layered sheet made of radially deployed neurons in early small mammals descended from reptiles during Triassic/Jurassic transition periods

Subtopics:

How the neocortex evolved

-mammals had small forebrains with little neocortex

>had olfactory bulb and olfactory cortex

-sensory perception

>Anterior and lateral somatosensory cortices didn’t change as much as motor cortex in early primates

-motor functions

>early primates had a region of granular frontal cortex with sensory inputs and connections with dorsal and ventral premotor areas

> frontal motor regions were enlarged and subdivided in early primates

Genetic differences between the neocortex in humans and in other species

3

-Increases in size and complexity of the cerebral cortex has culminated in the modern human that had separated from the mouse line between 90 and 100 million years ago and from the Old World monkeys

-use EVO DEVO

-In developing monkey and human neocortex, cells with similar morphology to RG, but not necessarily spanning ventricle to pia, are found outside of the VZ

-early primates had acquired a number of features of neocortex that now distinguish modern primate

>early primates had an array of new visual areas, and those visual areas widely shared with other mammals had been modified

>The primary and secondary visual areas, V1 and V2, exist in nearly all mammals, but these areas have specialized features in primates

-feature of cortical development in all mammalian species is that none of its constituent neurons is generated within the cortex itself

>are generated in the transient proliferative embryonic zones (VZ, SVZ) situated near the surface of the cerebral lateral ventricles; and, after their last cell division, then acquire their proper areal and laminar positions through long-distance radial and tangential migration across intermediate zone

4

How using EVO-DEVO can help us gain insight into the evolution of the neocortex

-compares how our genes are similar to other species and also extremely different from other species

-how novel features may have been created by gene mutation and, if inherited, propagated during evolution by natural selection

-only way to understand cortical evolution at the cellular level is by comparison of the differential gene expression and developmental events during embryonic development in living mammals

How new molecular pathways formed within the neocortex

-several features of cortical development that differ from the development of other organs of the body and even from the rest of the brain

-cerebral cortex is a cellular sheet composed of projection (or pyramidal) and local circuit neurons (or interneurons) deployed in horizontal layers, intersected by vertical (or radial) columns that are stereotypically interconnected in the vertical dimension and share extrinsic connectivity

>exhibits different degrees of variability in each area depending on their function

>pronounced in the large and convoluted human neocortex, with more that 50 distinct cytoarchitectonic areas that were described more than a century ago

>“inside-out gradient of neurogenesis

5

Backup Evidence

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3787901/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2349093/

Conclusion

-Using the process of evo-devo, the evolution of the neocortex can be further explored. We can delve into more of how its expansion has benefited the human race over time.

-increase in sub-ventricular neurogenic divisions is the reason for the dramatic increase in neuron number in the evolution of the human cerebral neocortex

-better identification of mechanisms regulating large brain size will depend on a detailed description of cellular behaviors, signaling pathways, and gene expression patterns

Looking for a Similar Assignment? Order now and Get 10% Discount! Use Coupon Code “Newclient”