Biospychology- synaptic transmission Flashcards
What is synaptic transmission?
The process in which one neuron communicates with another by releasing neurotransmitters to diffuse across the synapse.
What is the synaptic gap?
– Neurons do not make direct contact the synapse is the gap of the end of the axon of one neuron and the dendrite or cell body of another.
What is a neurotransmitter?
- as the electrical signal arrives at the end of the axon terminal of the pre-synaptic neuron, it causes a chemical to be released across the synapse.
-On the other side of the signup there are receptors located on the receiving neuron.
-the neurotransmitter binds to receptors whose shape fits this neurotransmitter.
-This activation of the receptors determines whether the post-synaptic neuron will generate an electrical signal.
What is the action potential?
– also known as an electrical impulse.
-When a new one is in arresting state it is negatively charged compared to the outside when a new one is activated by a stimulus. If this causes to become more positive charge for a split second it causes an action potential to travel down the axon.
What is the process of action potential?
– An action potential travels down the axon of the pre-synaptic neuron.
– When it reaches the terminal buttons it causes vesicles to migrate and bind with the pre-synaptic membrane triggering the release of a neurotransmitter.
– Neurotransmitters are then released back into the signups and go through the process of reuptake or get metabolised.
- Once activated the receptors produce either excitatory or inhibitory effects on the post-synaptic.
– Neurotransmitters diffuse across the signups and bind with post synaptic receptors.
(Exam question)
Outline the structures and processes involved in a synaptic transmission. 4 marks.
- An action potential travels along the axon of the pre-synaptic neuron.
- This triggers the vesicles to my great towards and find to the pre-synaptic membrane and release chemical messages called neurotransmitters.
- These chemicals diffuse across synapse and bind with post-synaptic receptors like a lock and key.
- This binding stimulates the synaptic neuron to transmit the action potential if the electrical signal charge reaches the required threshold.
- The neurotransmitter is then released from the receptor and is re-absorbed in the pre-optic neuron or metabolised.
What are excitatory effects in neurotransmitters?
They facilitate the firing of action potentials promoting alertness and activity.
What is inhibitory effects on neurotransmitters?
They help to calm the mind and body and are often involved in inducing sleep. (Off switches).
What happens when a neurotransmitter causes an inhibitory effect?
It causes the generation of an inhibitory post-synaptic potential IPSP leading to a negative charge at the post synaptic membrane.
What can happen when a neurotransmitter causes an excitatory effect?
It can lead to the generation of an excitatory post synoptic potential (EPSP) leading to positive charge at the post synaptic membrane.
What is summation?
The net sum of the total IPSPs and EPSPs which determines whether or not the cell fires. the threshold is -60 V for an action potential to be created.
What is temporal summation?
The combined effect of input over time.
What is spatial summation?
The combined effects of inputs across multiple neurons.
