Biopsychology : Synaptic Transmission Flashcards
What is the process of synaptic transmission?
Where one neuron communicates with another by releasing neurotransmitters to diffuse across the synapse
Whats the synapse?
the gap of the end of the axon of one neuron and the dendrite or cell body of another
How does a neurotransmitter work?
• electrical signal (nerve impulse) → action potential, passes through neuron to reach axon terminal or the pre-synaptic terminal
• it causes a chemical (neurotransmitter) to release across the synapse as the vesicles containing the neurotransmitter binds with the membrane of the pre-synaptic neuron and released the neurotransmitters
• on the other side, post-synaptic receptors receive the neurotransmitters and they bind together with the receptors that fit
• the post synaptic neuron is activated and generates an electric signal that passes on to the next neuron
How does action potential work?
Electrical impulse – when a neuron is resting its negatively charged vs the outside. When it’s activated by a stimulus, its positively charged for a split second which causes the action potential to travel down the axon
How does an action potential cause release of a neurotransmitter?
• Action potential travels down the axon of the pre synaptic neuron
• At the terminal buttons, it caused vesicles to migrate and bind with the pre synaptic membrane, triggering the release of a neuron
• Neurotransmitters are then released back into the synapse and go through re-uptake or get metabolised
• Once activated, receptors produce either excitatory or inhibitory effects on the postsynaptic neuron
• Neurotransmitters diffuse across the synapse and bind with their corresponding postsynaptic receptors
Types of neurotransmitters - Adrenaline
• fight or flight
• produced in stressful situations
• Inc heart rate, blood flow, etc, leading to physical boost and heightened awareness
Types of neurotransmitters - Noradrenaline
• concentration
• affects attention and responding actions in the brain
• Contracts blood vessels, inc blood flow
Types of neurotransmitters - Dopamine
• pleasure
• feelings of pleasure, addiction, movement and motivation
• people repeat behaviours that lead to dopamine release
Types of neurotransmitters - Serotonin
• mood
• well being and happiness. Helps sleep cycle and digestive system regulation
• affected by exercise and light exposure
Types of neurotransmitters - GABA
• calming
• calms firing nerves in CNS
• high level improve focus, low cause anxiety
Types of neurotransmitters - Acetylcholine
• learning
• involved in thought, learning and memory, associated with attention and awakening
• activates muscle action in the body
Types of neurotransmitters - Glutamate
• memory
• most common
• involved in learning and memory
• regulates development and creation of nerve contacts
Whats an EPSP?
Excitatory post synaptic potential (EPSP) → leads to a positive charge at post-synaptic membrane. Makes inside of post-synaptic neurone less negative vs outside, moving membrane potential closer to threshold needed to trigger action potential → more likely neurone will fire
How does excitation work?
act as ‘on switches’ → facilitate the firing of action potential, promoting alertness and activity
Whats an IPSP?
Inhibitory post synaptic potential (IPSP) → negative charge at post-synaptic membrane. Makes inside of post synaptic neuron more negative vs outside, moving membrane potential further from threshold needed to trigger action potential → less likely to fire
