1. Chapter 2: Biology, Neurons, and Brain Imagery

2. Case Study
SM: The No-Fear Woman

3. Why is learning to play an instrument good for the brain?

4. Introduction
At birth have extra supply of nerve cells; stabilizes in adolescence
200,000 will die every day of your adult life
you will end up with 98% of your supply by the time you’re 70

5. Neurons
Individual cells in nervous system that receive, integrate, & transmit info

6. Parts of the Neuron
1. Soma: is the cell body, which contains the nucleus.
2. Dendrites: (Greek for tree)
branching extensions that receive incoming messages and conduct messages toward the cell body.

7. Parts of A Neuron
3. Axon: extension of a neuron which takes messages from the soma to other neurons, muscles or glands
Longest part of the neuron
4. Myelin Sheath: white fatty substance around axons; allows faster transmission speeds of signals
Multiple sclerosis leads to deterioration
Slows communication to muscles – loss of muscle control

8. How does a neuron communicate?
Resting Potential: neuron is in its normal, resting state
Ions within the cell give the axon a small negative charge, fluid outside is positive charged
When the cell body becomes excited, triggers a cascade of events (like setting a little fuse on fire and keeps going until it blows up)
Action potential: temporarily reverses the charge (positive) and causes an electrical signal to race along the axon. (200 mph)
Happens when sense receptors feel something
Chain reaction along axon to end

9. How does a neuron communicate?
Refractory Period – neuron pumps the positively charged sodium ions back outside (pausing to recharge)

10. How Does A Neuron Communicate?
Some signals are excitatory – (pushing on accelerator); some are inhibitory (pushing on brakes)
If excitatory signals exceed maximum intensity (threshold) it will trigger an action potential
All or none principle: it fires or it doesn’t (doesn’t differ in intensity)
Whole cycle takes less than 1/100th of a second

11. Neuron Communication With Other Neurons
In order for one neuron to communicate with another it must pass a junction or gap called the synapse between the axon which is sending the signal and the dendrite which is receiving the signal.
At the ends of the axon, the terminal buttons release neurotransmitters: which are chemical messengers that bind together neurons and influence whether another neural impulse will take place.

12. Neural communication Reuptake- regulates amount of NT
Drugs affect neural communication at the synapse
Antidepressants often act as reuptake initiators and helps regulate
Insomnia is regulated by serotonin
Chemicals Homework: look up all of these neurotransmitters, (1) identify and define (2) look up the effects of too much or too little of each (3) be prepare to share them tomorrow
Dopamine Acetylcholine
Serotonin GABA
Norepinephrine Glutamine

13. Neuron Communication

14. Glial Cells
Glial Cells: provide structural support, nourishment and insulation of neurons, maintains chemical environment
Helps in forming new synapses
New research suggests may be crucial in part of the process of learning
Form a myelin sheath-fatty insulation around some axons in brain and spinal cord
Helps speed up neural impulses
Multiple sclerosis is a disease in which the myelin sheath degenerates-leads to loss of muscle control

15. Label the Parts of the Neuron

16. Types of Neurotransmitters…These Are Tough!!
1. Acetylcholine: vital role in learning and memory but most well known for its presence in allowing muscle contraction.
Shortage may lead may lead to Alzheimer’s disease or muscular disorders.

17. Types of Neurotransmitters…These Are Tough!!
2. Serotonin: affects mood, hunger, and arousal.
Shortage may lead to depression
3. Dopamine: influences movement, attention, and emotion.
Excess may lead to schizophrenia and Parkinson’s disease.

18. Types of Neurotransmitters…These Are Tough!!
4. Norepinephrine: helps control alertness and arousal when you are scared or excited.
5. Endorphins: called the “morphine within” because of its link to pain control and pleasure.

19. Types of Neurotransmitters…These Are Tough!!
GABA: helps relax and calm down the body.
– Shortage may cause Anxiety or Epilepsy.

20. Drugs can be….. Agonists- make neuron fire
Antagonists- stop neural firing
Reuptake Inhibitors- block reuptake

21. Agonists vs. Antagonists
Agonists are chemicals that mimic the effects of a neurotransmitter. Ex:
Antagonists are chemicals that block the transmission of a neurotransmitter. Ex: