1. Neurons and Synaptic Transmission

2. Lesson Objectives
Understand the different functions of the parts of a neuron
Understand and be able to explain synaptic transmission

3. The structure and function of the 3 different neurons.
The brain is essentially made up of billions of neurons – the exact number is unknown.
Each Neuron has up to 10,000 connections (synapses).
Neurons make up around 10% of the brains cells.

4. The structure and function of the 3 different neurons.
The rest of the brain is made up of Glial Cells – which are essentially there to supply essential nutrients, clean up and insulate/separate neurons from one another.
Neurons are responsible for everything we do – emotions, memories, thoughts and physical sensations and co-ordination of all the functions of the body

5. What are the main parts of a neuron?
Synapses,
Myelin sheaths,
Axon
Soma
Nucleus
Dendrites
Sweetie DNA! But…
Can you make a sweetie neuron?!

6. Biological Psychology
Build a sweetie neuron
Using the sweets provided build a technically accurate neuron on a blank sheet of paper.
Decide which type of neuron you will make.
Label it appropriately, defining all key terms.
Show or describe how it transmits an electrical impulse or ‘fires’
Once finished take a snap of it and print it and stick in your books. 

8. Types of Nerve Cells

9. A nerve cell, or a neuron, consists of many different parts.
What kind of a neuron is this? (Motor neurone)
What’s the difference between the different neurons?
Preview Question 1: What are neurons, and how do they transmit information?

10. Lets label a synaptic transmission

11. The Synapse

12. Synaptic Transmission
Messages travel from one neuron to the next across gaps in nerve cells called SYNAPSES.
At these gaps, the messages go from being ELECTRICAL to CHEMICAL in nature.
So when the electrical impulse reaches the end of the neuron it triggers the release of neurotransmitter.

13. Neurotransmitters
Neurotransmitters are chemicals that diffuse across the synapse to the next neuron in the chain.
Once it crosses the gap it is taken up by the postsynaptic receptor site (The dendrites on the other neuron) > The Neurotransmitter is then converted back into an electrical impulse and the process of transmission begins again for this other neuron.

14. Neurotransmitters
There are several types of neurotransmitters that have been identified and each of them have their own specific function and molecular structure.

15. Neurotransmitter
Function
Dopamine
Increases addictive effects of reinforcement, contributes to control of movement; linked with schizophrenia, Parkinson's disease and addiction
Serotonin
Associated with mood, eating, arousal (including sleep); linked with depression, aggression, OCD, eating disorders.
Noradrenaline
Increases arousal, attentiveness and sexual behaviour; released as a hormone during stress, linked with depression.
Adrenaline
Associated with lack of focus and fatigue, anxiety, attention deficit hyperactivity disorder (ADHD), sleep problems.
Acetylcholine
Involved in learning, memory, rapid eye movement sleep, linked with ADHD and Parkinson's disease
Gamma-aminobutyric acid (GABA)
The main inhibitory neurotransmitter, linked with epilepsy.

16. Synaptic Transmission
THIS HAS NOTHING TO DO WITH SPEED!!!
Synaptic Transmission
At the synapse, neurotransmitters are released which will either have an excitatory or inhibitory effect on the next neuron.
Excitatory potentials - increase the chance of a neuron firing (accelerator - go)
Inhibitory potentials- decrease the chance of a neuron firing (brake – don’t go)
The sum of these potentials will decide whether or not the neuron fires (a process called SUMMATION)

17. Excitatory or inhibitory neurotransmitters
Biological Psychology
Excitatory or inhibitory neurotransmitters
5:25
Some neurotransmitters are excitatory and some are inhibitory in terms of their effect on the neighbouring neuron.
Inhibitory – neuron becomes negatively charged and less likely to fire. (Serotonin)
Excitatory – neuron becomes positively charged and more likely to fire. (Adrenaline, like in fight or flight!)

18.
6.30

19. Sum up Summation
2.38

20. Apply it: The Reflex Arc!
Biological Psychology
Apply it: The Reflex Arc!
The reflex arc (fill in the blanks using the key words at the bottom)
The knee-jerk is an example of a reflex arc:
A stimulus, such as a hammer, hits the knee. This is detected by sense organs in the ________________________, which convey a message along a _________________________.
The message reaches the _________________________, where it connects with a ______________________. This then transfers the message to a ________________________. This then carries the message to an ___________________, such as a muscle, which causes the muscle to contract and, hence, causes the knee to move or jerk.
Missing words:
Effector, sensory neuron, motor neuron, relay neuron, CNS (central nervous system), PNS (peripheral nervous system)