Chapter 1 Neuroscience: Past, Present, and Future

Chapter 1Neuroscience: Past, Present, and Future

Introduction

• Various aspects of human nature– Curiosity, pain, pleasure,

movement, reasoning, learning, memory, emotion, and madness

• Neuroscience– Study of the brain

• The Society for Neuroscience

• Prehistoric ancestors – Brain vital to life

• Skull surgeries – Evidence: Trepanation– Skulls show signs of

healing

• Views of ancient Egypt– Heart: Seat of soul and

memory (not the head)

• Views of the Brain: Ancient Greece

– Correlation between structure and function

– Hippocrates

• Brain: Involved in sensation; seat of intelligence

Hippocrates (460-379 B.C.E.) – first ascribed to the brain the role of the organ of sensation.

Aristotle (384-322 B.C.E.) – felt the heart was the center of intellect and believed the brain was more a “radiator” to cool

the body.

Galen (130-200 A.D.) – Greek physician who tried to deduce function of the brain from structure of the cerebrum and cerebellum. He put forth a model for

brain function that was the start of the fluid-mehcanical theory.

• Views of the Brain: The Roman Empire– Views of Greek physician Galen

•Cerebrum•Cerebellum•Ventricles

• Views of the Brain: The Renaissance

– The brain as a machine

• Views of the Brain: The Renaissance

– Fluid-mechanical theory of brain function

– Philosophical mind-brain problem

Andreas Vesalius – publishes On the Workings of the Human Body in 1543

Another example of one of his drawings.

Rene’ Descartes – (1596-1650) one of the most important Western philosophers and scientists who promoted the idea of the brain function

occurring via the fluid-mechanical theory

Benjamin Franklin publishes Experiments and Observations on Electricity in 1751. His notions on electricity paved the way for a new

theory of neural function.

Luigi Galvani Emil du Bois-Reymond

These two researchers were responsible for determining the interaction

between electricity and the brain.

Charles Bell Francois Magendie

These two conducted experiments that answered the question on whether the movement in a nerve was bidirectional or

unidirectional.

• Views of the Brain: The Nineteenth Century

– Nerve as wires, understanding of electrical phenomena, nervous system can generate electricity

– Bell and Magendie: Dorsal and ventral roots carry information in opposite directions

Franz Joseph Gall (1758-1828) was the founder of phrenology.

Franz Joseph Gall Paul Broca

Gall described the concept of phrenology.

Broca first identified a region of the cerebrum being associated with function.

Charles Darwin – his theory of natural selection helped to explain the growth and development of the brain.

• Evolution of the Nervous System– Natural selection– Nervous systems of different

species may share common mechanisms

– Rationale for “animal models”

Theodor Schwann proposed the cell theory…. ALL TISSUES ARE COMPOSED OF CELLS

Otto Deiters (1865) – identified the major parts of the neuron and predicted the communication and interactionbetween the axon and dendrites.

Neuroscience Today

• Reductionist approach

– Levels of analysis•Molecular•Cellular•Systems•Behavioral•Cognitive

Levels of Analysis can be applied to Neuroscience

• The Use of Animals in Neuroscience Research

– Animals: Renewable natural resources – The more basic the process under

investigation, the more distant the evolutionary relationship with humans

• Examples (from simple to more complex) - nematodes, insects, snails, squid, rodents, monkeys, etc.

• Animal rights• Philosophy• Abolition of animal use• Animal rights activists

• The Neuroscientist -Education, Training, Research experience -Clinical vs. Experimental research

• The Cost of Ignorance: Nervous System Disorders