1. Introduction

2.  Complexities occurring even with simplest function ◦ Example

3. synapse Structure of the neuron

4.  Neuron- individual cells in our nervous system that receive, integrate and transmit information.  Components of a neuron: ◦ A.) cell body (soma)- contains nucleus and chemical machinery ◦ B.) Dendrites – Part of neurons that receive information  “Branches”

5.  Components of neuron (continued) ◦ C.) Axon- Long thin fiber that transmits signals from cell body to other neurons. ◦ D.) Myelin Sheath- Insulating material that coats an axon.  Speeds up transmission  Problems if it degrades  Easier way of thinking about axon and myelin sheath

6. ◦ E.) Terminal Buttons- Axon ends with a cluster of these small knobs secreting chemicals known as neurotransmitters. ◦ F.) Synapse – A “Gap” or junction where information is transmitted from one neuron to another.  Summary of neural communication: ◦ Dendrites  cell body  axon (coated with myelin sheath)  terminal buttons  synapse at other dendrites(where signal jumps gap) ◦ Process repeats itself

7.  Neural Impulse- Signal sent through neuron  Neuron at rest: ◦ Slightly negative charge ◦ Contains ions flowing back and forth  Charge is referred to as Resting Potential- charge when a neuron is not activated

9.  When neuron is activated, channels open allowing in positive ions (+) ◦ Charge now becomes positive  Called Action Potential- Brief shift in neuron charge that travels along axon.  Channel closes briefly after firing: ◦ Absolute Refractory Period- Minimum length of time after action potential during which another action potential can’t begin

10.  Neurons either fire or do not (action potentials occur or don’t)

11.  Transmission of signals from one neuron to another (at dendrites) occurs here  At this gap, the arrival of action potential triggers release of neurotransmitters.

13.  Neurotransmitter- Chemical that transmits information from one neuron to another ◦ Play role in behavior ◦ Specific ones function at specific synapses  Example Neurotransmitters: ◦ Dopamine ◦ Norepinephrine ◦ Serotonin ◦ Endorphins  Certain chemicals or drugs can cause increase or decrease in release.

14.  Dopamine- Pleasurable emotions  Norepinephrine- contributes to mood and arousal  Serotonin- plays role in depression  Endorphins- Body’s own internally produced morphine like substance ◦ Plays role in pain relief