Neuroscience

1
Chapter 3 Neuroscience Biological Foundations
2
The Nervous System
CNS
3
Neurons

• Neurons are composed of
• Cell body (soma) directs actions of the cell
• Dendrites extensions that receive information
• Axon extends from cell body, carries electrical
  potential, sends a chemical message to adjacent
  neurons via terminal buttons

4
The Action Potential
5
At rest, the inside of the neuron negative
relative due to a higher concentration of
positively charged ions outside the neuron. 
When stimulated, sodium channels open and
positively charged sodium ions rush into the
axon, depolarization a small region within the
axon. 
The region of depolarization causes nearby sodium
channels to open. Just after the sodium channels
close, the potassium channels open wide, and
potassium exits the axon, repolarizing the tissue
just behind the action potential.
This process continues as a chain-reaction along
the axon.  The influx of sodium depolarizes the
axon, and the outflow of potassium repolarizes
the axon. 
The sodium/potassium pump restores the resting
concentrations of sodium and potassium ions 
http//intro.bio.umb.edu/111-112/112s99Lect/neuro_
anims/a_p_anim1/WW3.htm
6
Myelinated Axons
7
Neurons are for Communicating
8
Synapse
9
Neurotransmitters

• Serotonin affects mood, sleep, sensory
  perception, and other functions, may play a role
  in psychological disorders like depression
• Acetylcholine involved in memory, muscle
  action, sleep, emotions, those w/ Alzheimers
  have lower levels
• Dopamine affects movement, attention, memory,
  learning, plays role in addiction
• Norepinephrine affects learning, memory,
  emotions, eating, alertness, etc.
• Epinephrine emotions, memory storage

10
Nicotine is an acetylcholine agonist
Curare is an acetylcholine antagonist
11
The Nervous System
CNS Central Nervous System PNS Peripheral
Nervous System
12
Peripheral Nervous System

• PNS includes all nerves outside the brain and
  spinal cord
• Broken down into somatic and autonomic nervous
  systems
• Somatic NS carries sensory messages to brain and
  motor commands to the muscles

Somatic Nervous System
13
Peripheral Nervous System

• Autonomic N.S. regulates automatic body functions
  (heart rate, breathing)
• Sympathetic Fight or Flight
• Parasympathetic Active during digestion

14
Autonomic Nervous System
Parasympathetic
Sympathetic
calms
arouses
15
The Spinal Cord
16
Midline Brain ViewLower Level Brain
Structures-oldest part of the brain

• 3 major Brain Stem Structures
• Pons
• Medulla
• Reticular Formation

17
Midline Brain View
Corpus Callosum connects 2 brain hemispheres
Thalamus Sensory relay area
Hypo- Thalamus 4 Fs Feeding, Fleeing,
Fighting Mating
Cere- Bellum - Smoothes movements
18
(No Transcript)
19
the cerebral cortex...
20
4 lobes of the cerebral cortex Frontal,
Parietal, Occipital, Temporal (F-POT)
Frontal Lobes Motor Control, Speech Production,
Higher Functions
Brocas Area
21
Phineas Gage 1823 - 1861
22
4 lobes of the cerebral cortex Frontal,
Parietal, Occipital, Temporal (F-POT)
23
(No Transcript)
24
(No Transcript)
25
Occipital Lobes
26
(No Transcript)
27
(No Transcript)
28
Summary of Hemispheric Specializations-lateral
ization
29
Studying the Brain

• Lesion studies a brain region is destroyed and
  behavior is observed
• Lesions of hypothalamus in animals ---gt
  overeating
• Strokes interrupt blood flow in brain ---gt damage
  brain

30
Studying the Brain

• Electrical Recording overall brain wave
  activity monitored by electroencephalograph (EEG)
• Electrical Stimulation of the Brain (ESB)

31
Studying the Brain

• Imaging techniques allow the living brain to be
  studied for its activity during behavior
• CT scans (computed tomography) used to detect
  brain structure abnormalities in people w/ mental
  illness

left temporal tumor
meningitis
32
Studying the Brain

• PET scans use radioactive glucose to assess brain
  activity

Control Ecstasy User
33
Studying the Brain
MRI Scan of Tumor in Speech Center

• MRI scans generate 3D views of the human brain
• fMRI faster version of MRI

MRI for Face Recognition in Normal Volunteer gt