2. Objectives
• Understand the hierarchal organization of
the brain, neuron and synapse
• Understand the sequence of event involved
in communication at the synapse
• Understand the synaptic transmission
involves neurotransmitters that may be
either excitatory or inhibitory
3. The Brain
• Approximately 3 lbs
• Contains billions of cells
– Nerve cells (neurons)
– Glial cells (glia)
7. The Synapse (The connection between)
• Presynaptic neuron
– The neuron whose axon forms the synapse
with the dendrite of another neuron
– Sends out information
• Postsynaptic neuron
– The neuron whose dendrite forms a synapse
with the axon of the presynaptic neuron
– Receives information
8. The Reward System
• Ventral Tegmental Area (VTA)
• Nucleus accumbens
• Frontal region of cerebral cortex
9. Neurons Use Electrical and Chemical Signals
to Transmit Information
• Neurons use electrical impulse (action
potential) to relay information from one
part of a neuron to another
• Neuron coverts the electrical signal to a
chemical signal (neurotransmitter)
• Target neuron then converts the message
back to an electrical impulse to continue
the process
10. Activity: How Do Neurons Communicate?
Before we begin….
What is the purpose of a synapse?
How do neurons regulate body
functions, behaviors, and emotions?
14. Activity: Neurotransmitter Actions
• Analyze the effects of different
neurotransmitters on the activity of a
neuron
• Answer the questions on worksheet 2.7
15. Activity: One Neuron Signals Another
• Complete worksheet 2.8B
• We will do Case “A” together
Editor's Notes
MASTER 2.1
Cell body metabolic center of the neuron
Nucleus located here
most proteins made here
Dendrites specialized cell processes or fibers that extend from the cell body
branched fibrous processes
specialized to receive input and carry information toward the cell body
Axon larger in diameter than the dendrites
specialized to carry information away from the cell body
May be very long. Some axons are over 1 meter long
Top of Master 2.2
Point out the axon terminals of one neuron end near the dendrites of another neuron
Bottom of Master 2.2
The cell bodies of the neurons that drugs affect are located in the VTA. Those cells extend their axons to nerve cells in the nucleus accumbens. Some nerve fibers extend to part of the frontal region of the cerebral cortex
Refer to Pg 46 for further explanation
Master 2.3
Purpose= connect neurons (not physically but functionally). Enable neurons to communicate by passing signals between them
Function= by passing signals across the synapse from one neuron to the next. These signals dictate whether the receiving neuron is activated.
Directions for activity: Look at and discuss the diagrams. As partners, write a summary of how you believe the neurons are interacting at each step.
Video
Now complete MASTER 2.5 using the appropriate terminology
MASTER 2.6
Refer to page 48
Different neurotransmitters fulfill different functions in the brain. Some neurotransmitters
act to stimulate the firing of a postsynaptic neuron. Neurotransmitters that act this way are called excitatory neurotransmitters because they lead to changes that generate an action
potential in the responding neuron. Other neurotransmitters, called inhibitory neurotransmitters, tend to block the changes that cause an action potential to be generated in the responding cell.
