Neuron Chapter 1

structure to behavior flow

structure → signal → circuit → function → behavior

Neuroscience

focuses on how the human nervous system is organized and functions, and what happens when neurological or psychiatric disorders affect it

considers various aspects of human nature (pain, curiosity, pleasure, movement, reasoning, learning, anger)

First Society of Neuroscience Meeting

1971 - First Annural Meeting of Society of Neuroscience

What could scientists do or observe to study neuroscience? (5)

• obeserve behavior after injury (what abilities change when a particular part of he nervous system is damaged)

• dissections of nervous tissue

• compare species

• stimulate nervous tissue

• interrupt neural pathway

What could scientists conclude from evidence? (6)

• where is the function located?

• what direction does information travel?

• how are the signals transmitted?

• is the brain region required for a specific function?

• can activating a brain region produce a function?

• how does brain activity produce behavior?

Prehistoric Ancestors

• brain = vital to life

• skull surgeries

  • trepanation → relieving pressure in the brain

  • basically cutting into the meningis

  • CONNECTS TO BURR HOLE TODAY - HEMATOME IS BLOOD POOLA IN THE MENINGISIS AND DURA HAVE TO RELIEVE PRESSURE

    • CRANIOTOMY COMPLETELY REMOVING THE SKULL PORTION - ANESTHESIA

    • TWIST DRILL

    • BURR HOLE - ANESTHESIA

  • signs of healing visible

• ancient egypt

  • heart = seat of soul and memory

400 BCE Hippocrates & Aristotle

hippocrates

• brain involved in sensation, associated with intelligence, neurological symptoms are brain based

aristotle

• heart as a center of intelligence, brain kind of seen as cooling center

Galen 2nd CE (begins structure function reasoning)

• animal dissections, revealing the cerebrum and cerebellum

• sulci and gyros

• noticed the two hemisphere, longitudinal fisher, dissection into the lateral lobes revealed fluid (humor?? → some sort of spirit thing)

softer cerebrum → sensation/perception

hard cerebellum → movement

^^^^ right conclusions but not correct reasoning

emphasized ventricles and interpreted brain function through prevailing some sort of fluid machine model with the fluid and humor basically the fluid control everything else in the body

Vesalius → renaissance to the 17th century

gray vs. white matter

surfance of the brain → gray matter cerebral cortex

inside the brain → white matter (fluid inside will control and send to the body)

myelin wraps around neuron → appear white under the microscope (didn’t know this until microscope)

Descartes → Renaissance to 17th Century

• retained mechanical/hydraulic model of neural function

• brain as a machine (Proposed Theory)

• mind and brain interacted via pineal gland

18th Century

Experimental physiology

basic sensation (where you are, where your arms are) → post central sulcus

parietal lobe

peripheral nervous systems are just like any nerves throughout the body and central nervous system is just the brain and spinal cord

Brain as a Machine Model

Brain → Fluid → Hollow Nerve → Muscle

Understanding Stiumlation

du Bois - Reymond & Luigi Galvani:

• showed that muscles can twitch when nerves are stimulated

• brain can generate electricity

Bell-Magendie

• signal directionality

• dorsal and ventral roots were cut separately

• ventral root cut = muscle paralysis (motor) → signals starting at the brain and going out

• dorsal root (back) = loss of sensation → signals going up to the brain and spinal cord

• also moves from fluid model to a more electrical model because if you cut something it no longer works → so move away from fluid and machine model

Localization of Brain Function

• Charles Bell

  • cerebellum: origin of the motor fibers

  • cerebrum: destination of sensory fibers

• Pierre Flourens

  • cerebella damage strongly implicated the cerebellum in coordinated movement

• Gall

  • bumps on the brain correlate to personality (FALSE)

Broca

Broca Aphasia: patients understand and register what’s going on but they can convey the infomration

• discrete region of human cerebrum for speech, particularly left-hemisphere

• CORTICOL Localization

Localization of Brain Function

• Brain Electrical Stimulation

  • stimulation of specific cortical localization produced movements generally on the opposite sides

• Penfield

  • applied mild electrical stimulation to see movement sensation

  • homunculous → found in parietal lobe (mapping of receptors on hands or face etc)

  • frontal lobe → more about like movement

Charles Darwin

made important contributions (comparative biology)

natural selection, conserved neural mechanisms allow animal studies to reveal principles that are still relevant to humans

monkey much better at seeing and rat is better at like feeling

Schwann

Cell theory and Microscope

neurons are essential, glial cells important, neurons are basic functional unit of brain, receive, integrate, and process signals but not in isolation, multipolar neuron in brain

Levels of Neuroscience

Molecular neuroscience:

• genes, channels, receptors, transmitters

Cellular Neuroscience:

• neurons, neuroglia, synapse

Systems Neuroscience:

• circuits, pathways, lateral connection

Behavioral Neuroscience:

• action, learning, motivation, sleep

Cognitive Neuroscience:

• language, memory, decisions, awareness (conciousness)

Parkinson’s Disease

a disease where there is issues with motor neurons → muscles

affecting all muscles

symptoms:

• tremors (skeletal muscles are affected)

• bradykinesia (slow movement)

• muscle rigidity, balance and posture, speech and writing, mood changes, constipation

Parkinson’s at Different Levels

Molecular: dopamine

Cellular Level: degeneration of substantia nigra (inside of the mid brain)

systems level: sectioning of the brain, basal ganglia circuit

behavioral neuroscience: bradykinesis, tremors, rigidity

cognitive neuroscience: cognitive decline

Hubel and Wiesel: Studying Vision in Cats

understanding visual pathway, light goes into eye and then occipital lobe

Eric Kandel: Learning and Memory in Sea Slugs

teaching sea slugs stuff