Neurotransmitters and neuromodulators Flashcards
Define a excitatory neurotransmitter
Neurotransmitters that have an excitatory effect that makes post-synaptic neurons more likely to fire an action potential
Define a inhibitory neurotransmitter
Neurotransmitters that have an inhibitory effect that makes post-synaptic neurons less likely to fire an action potential
Define GABA (Gamma-amino butyric acid)
The main inhibitory neurotransmitter in the CNS that works through the brain to make post-synaptic neurons less likely to fire & keeps you calm
Define Glutamate
The main excitatory neurotransmitter in the CNS, it enhances information transmissions by making post-synaptic neurons more likely to fire
More glutamate = ?
LTP
Less glutamate = ?
LTD
What is glutamates role in neural plasticity?
Glutamate is needed for synaptic plasticity to occur, and does the following:
- Helps to activate post-synaptic neurons
- Produces long lasting changes to synapse (synaptogenesis)
Define neuromodulators
Chemical molecules released by the neuron that have an effect on multiple post-synaptic neurons & alter the effectiveness of neural transmission
Define dopamine
A neuromodulator primarily responsible for voluntary motor movement, experience of pleasure and reward based learning
What effects does dopamine have?
Inhibitory & excitatory effects
What is the reward pathway?
A group of structures in the brain activated by rewarding or reinforcing stimuli & is an important determinant of motivation.
Explain 1st step of process of dopamine in relation to hunger/food
- Dopaime levels decrease below the basline in the reward pathway
Explain 2st step of process of dopamine in relation to hunger/food
- Lower dopamine in the reward pathway results in sensation of hunger
Explain 3st step of process of dopamine in relation to hunger/food
- Sensation of hunger increases food seeking/eating behaviors
Explain 4st step of process of dopamine in relation to hunger/food
- Dopamine levels in reward pathway increase above baseline once you have eaten
Explain 5st step of process of dopamine in relation to hunger/food
- Pleasure is experienced and reinforces the pattern of the brain activity & behavior
How does addiction occur and how does it relate to dopamine?
When we see a ‘reward’ worth chasing our brain produces higher levels of dopamine and motivates us to complete the task (does not matter if it is unhealthy or difficult)
Explain the steps of the addiction cycle.
- Theres an increase of dopamine due to reward activities
- Increased dopamine produces feelings of pleasure
- Dopamine is produced less over time and diminishes the brain supply
- This causes an increase in the urge to continue and seek out the same feeling
- repeat
Define serotonin
Serotonin is primarily responsible for the regulation of mood and sleep
- Serotonin pathway is how serotonin is transmitted
Is serotonin inhibitory or excitatory?
Inhibitory
What are some relations between serotonin and mood?
- Higher levels of serotonin = mood improves
- Mid/balanced serotonin levels lead to calm, focused, happy and stable moods
- Low levels of serotonin has negative effects on the brains ability to regulate mood; this is commonly associated with depression and anxiety
Define sleep pressure
The pressure to sleep as you get tired; increases restlessness & wakefulness when you should be sleeping
Depending on the receptor site & the brain area it acts upon, what are 3 examples of roles/effects serotonin can have?
- Appetite
- Digestion
- Arousal
How many neurons (post-synaptic neurons) does neurotransmitters effect?
1 or 2 post-synaptic neurons
