User:Deroberm/Paleoneurology

Wikipedia Proposal: Paleoneurology'

Presented by: Michael Derobertis, Lauren Okada, Ryan Scully, Hope Jin

History

Humans have had a long interest in the brain and its functions. The first recorded study of the brain and its functions was from a papyrus text written by the ancient Egyptians during the 17th century BCE. The document details 48 medical ailments and makes references to how to deal with head wounds. Much later in the 6th century BCE the ancient Greeks began to focus on studies of the brain and the relationship between the optic nerve and the brain. Studies of brain evolution, however, did not come about until much later in human history.

In the late part of the 18th century and the early part of the 19th century thought of brain evolution was beginning. Two main views of life sprung forth; rationalism and transcendentalism. These formed the basis for the thought of scientists in this period. Georges Cuvier and Étienne Geoffroy St. Hilaire sprung forth as leaders in the new field of comparative anatomy. Curvier believed in the ability to create a functional morphology based simply on empirical evidence. He stressed function of the organ must coincide with its form. Geoffroy put a heavy emphasis on intuition as a method of understanding. His thought was based on two principles: the principle of connections and the principle of unity of plan. He was one of the first to look for homologies in organs across species, though he believed that this was evidence of a universal plan, not decent with modification.

The late part of the 19th century in comparative anatomy was heavily influenced by the work of Darwin in the Origin of Species in 1859. This work completely changed the views of comparative anatomists. Within 8 years of Darwin's release of the origin of species, his views on decent from a common ancestor were widely accepted. This lead to a movement of trying to understand how different parts of the brain evolved.

The next major innovation which helped bring about paleoneurology was the microscope. The microscope was invented in the 17th century, but it was only used in biology in the late 19th century. The techniques on how to look at brain cells under a microscope took a long time to perfect. 1n 1873, with this tool in hand Camilo Golgi began to cellularly detail the brain and look at techniques to perfect axonal microscoping. Ludwig Edinger took advantage of this and came up with a new branch of anatomy called comparative neuroanatomy. Edinger held that vertebrates evolved in a linear progressive series. He also thought that changes in the brain were based on a series of additions and differentiations and that the most highly, complex brains were those that were the most encephalized.

The period of 1885-1935 was an explosion of ideas in comparative neuroanatomy. This era culminated in the publication of "The Comparative Anatomy of the Nervous System" by Arienns, Kappers, Huber, and Cosby. This explosion in ideas lead to Ottilie Edinger founding the branch of paleoneurology int the time period of 1935-1960. Her paper, Die Fossilem Gehime, lead to the basis of the new branch. She was the first to study fossil records of brains of vertebrates in order to understand the evolutionary mechanisms that occurred.

Main points

General definition

• Paleoneurology is the study of brain evolution by examining anatomical and morphological endocranial traits and volumes of endocasts.

Importance of Paleoneurolgy

• The study of paleoneurology allows researchers to determine the volume of the ancient brain. By finding these measurements, researchers have been able to predict the average body weight of species. Endocasts also reveal traits of the brain including relative lobe size, blood supply, and general insight into the evolution of species.

Methods of Research

• Paleoneurologists analyze endocranial casts (endoclasts) that reproduce details of the external morphology of brains that have been imprinted on the internal surfaces of skulls.

• Paleoneurologists identify cranial capacity of fossils, which approximates brain size.

Limitations

• Fossil preservation and lack of suitable experimental subjects hinder ability to record accurate findings on brain morphology from endocast analyses.

• Tools to study endocasts need refining.

History of Paleoneurology

• Studies of the brain have been tracked back to ancient Egypt. Paleoneurology did not come along until much later in 1819 when Oken published his results from petrified mud found in the skull of a crocodile in 1819.

• Darwin's publication of Origin of Species in 1859 led to speculations on vertebrate brain evolution.
• The history regarding paleoneurology can be broken into 5 main periods: (1) Transcendental Anatomy and the Chain of Being; (2) Victorian Neuroanatomy; (3) Microscopy and the Flowering of Comparative Neuroanatomy; (4) Evolutionary Synthesis and Experimental Neuroanatomy; and (5) Evolutionary Developmental Neuroanatomy.

Current Research Topics

• Original research studying relationship between hemispheric length, maximum endocranial width, and frontal width at Broca's area. Investigated in extant and extinct humans.
• Paleoneurology and midsagittal brain shape correlation with intelligence and cognitive performance - research study investigating connection between brain shape and mental speed. This study incorporated human subjects' cognitive testing in relationship to extinct humans.
• Scientists use of paleoneurology to understand evolution of degenerative neuronal disease affecting gait, hand, language, cognition, mood and behavior disorders

Division of workload:

Our group has decided to set up times throughout the semester to work together to finish the article. We believe this the best plan of attack to get the work done in a timely manner and understand what is going on.