1. Option E.4 Neurotransmitters & Synapses
Page 360

2. Synaptic Transmission
Neurons communicate with each other chemically across a space called a synapse
Presynaptic membrane
Sending
Postsynaptic membrane
Receiving
The molecule moving across the space (synaptic cleft) is called a neurotransmitter

3. Neurotransmitters Some NTs are excitatory Some NTs are inhibitory
Stimulate the next neuron to forward the message
Increase the permeability to positive ions (positive ions move in)
Some NTs are inhibitory
They cause positive ions to move out of the postsynaptic cell
Movement of positive ions back into the synaptic cleft chemically depresses the postsynaptic cell (harder to excite)

4. Question
When two neurons communicate with each other, the presynaptic neuron sends a message across the synapse to the postsynaptic neuron.
1. What type of molecule carries the message across the synapse and what type of molecule receives the message?
2. Explain the two ways that presynaptic neurons can act on postsynaptic neurons.

5. Decisions, decisions
What interaction occurs between excitatory and inhibitory presynaptic neurons acting at the synapse?
Open your book to page Read pages Then answer the following questions:
In your own words, outline the steps of decision making in the central nervous system.
Identify an excitatory neurotransmitter. Outline how an excitatory neurotransmitter works.
Identify an inhibitory neurotransmitter. Outline how an inhibitory neurotransmitter works.

6. Psychoactive drugs
Before we talk about how drugs affect the brain & personality, we need to have a fundamental understanding of two neurotransmitters:
Acetylcholine
Noradrenaline

7. Cholinergic vs. Adrenergic Synapses
Synapses using acetylcholine are called cholinergic synapses
Nicotine, for example, stimulates transmission in cholinergic synapses  calming effect
“C”
Synapses using noradrenaline are called adrenergic synapses
Cocaine & amphetamines stimulate adrenergic synapses  increased alertness, energy & euphoria
“A”

8. What’s amphetamine? Adderall (ADHD/cognitive control)
Sometimes prescribed “off label” for depression, obesity & nasal congestion

9. Effect of drugs on the brain
Drugs can alter your mood & emotional state
Excitatory drugs like nicotine, cocaine and amphetamine increase nerve transmission
Inhibitory drugs like benzodiazepines, alcohol and tetrahydrocannabinol (THC) decrease likelihood of nerve transmission

10. How can drugs change synaptic transmission?
Block a receptor for a neurotransmitter
Block release of a neurotransmitter
Enhance release of a neurotransmitter
Enhance neurotransmission by mimicking a neurotransmitter
Block removal of a neurotransmitter from the synapse and prolong the effects of the NT

11. EXCITATORY!!!! DRUGS Turn to page 365.
Explain the effects of nicotine, cocaine and amphetamine in terms of their actions at the synapses in the brain.

12. Inhibitory Drugs Turn to page 366.
Explain the effects of GABA, alcohol and THC in terms of their actions at the synapses in the brain.