62 Questions
Which type of synapse allows synchronised electrical activity among populations of neurons?
Electrical synapse
What is the function of glia in synaptic transmission and function?
Regulation of synaptic connectivity
Which of the following is NOT a component of a chemical synapse?
Electrical synapse
What is the mechanism of action of Botox and Tetanus toxins?
Inhibition of neurotransmitter release
What is the concept of the tripartite synapse?
Synaptic transmission involving two neurons and one glial cell
What are the locations of chemical signals and synapses mentioned in the text?
CNS and neuromuscular junction
What are the neurotransmitters involved in chemical synaptic transmission?
Glutamate and GABA
What are the functions of neurotransmitters mentioned in the text?
Release, recovery, and degradation
Which of the following is true about glial cells?
They are targeted by drugs and toxins
What is the role of synaptic communication in the nervous system?
To support neurons and regulate synaptic connectivity
Which cells does the tetanus toxin inhibit the release of neurotransmitters from?
Cholinergic neurons that innervate muscles
Which of the following diseases is NOT linked with glial cells?
Epilepsy
What is the main function of glial cells?
To regulate synaptic connectivity
Which of the following is true about synaptic transmission?
It relies on the release of neurotransmitters in response to an action potential
What is the role of glial cells in CNS regeneration potential?
To support neurons and regulate synaptic connectivity
Which of the following diseases is NOT mentioned as being linked with aberrant synaptic stripping?
Parkinson's disease
What is the importance of turning signals off during synaptic communication?
To prevent excessive signaling
Which of the following criteria define a neurotransmitter?
It is synthesized in the neuron and released in amounts sufficient to exert an effect on the postsynaptic neuron.
Which of the following is true about the actions of Botulinum toxin (Botox) and Tetanus toxin (TeTX)?
Botox acts at the neuromuscular junction, causing permanent muscle relaxation, while TeTX inhibits the release of glycine and GABA, resulting in permanent muscle contraction.
Which of the following is responsible for loading vesicles with H+ to make them acidic?
ATPase proton pump
Which of the following is true about glia?
Glia express neurotransmitter receptors and can change intracellular levels of Ca2+ in response to synaptic activity.
What is the role of calcium in synaptic vesicle release?
Calcium activates Calcium calmodulin activated kinase II (CaMKII) which phosphorylates synapsin, allowing vesicles to dock to the active zone.
Where does neurotransmitter release occur?
Presynaptic terminal
What is the purpose of endocytosis in synaptic vesicle release and recycling?
To recover the vesicle membrane rapidly
What is the role of synapsin in synaptic vesicle release and recycling?
To anchor vesicles to the cytoskeleton
What is the main function of the tri-partite synapse?
To control synapse function and plasticity
What is the function of neurotransmitters in synaptic transmission?
To depolarize the membrane of the next cell
Which of the following is NOT a function of glial cells?
Synthesizing neurotransmitters
What is the advantage of electrical synapses compared to chemical synapses?
They are faster
Which type of synapse allows synchronized electrical activity among populations of neurons?
Electrical synapse
What is the main focus of the next lecture?
The synthesis of neurotransmitters
What is the advantage of electrical synapses compared to chemical synapses?
They are bi-directional
When are electrical synapses most common?
During development when the nervous system is forming
What do drugs used in medicine act on?
All of the above
What is the function of synaptic communication in the nervous system?
To allow communication between neurons and organs
Which protein keeps the vesicles tethered to the plasma membrane?
SNARE complex
What happens to the vesicles in the recycling phase?
They are refilled with neurotransmitter
What is the role of glial cells in synaptic transmission?
Uptake and removal of neurotransmitters
What is the function of the voltage-gated calcium channels?
To release neurotransmitter into the synaptic cleft
What is the role of Botox in neuromuscular junctions?
It prevents neurotransmitter release
What is the consequence of tetanus toxin inhibiting the release of inhibitory neurotransmitters?
Muscles are always contracted
What can happen if the snare proteins on the presynaptic terminal are attacked by toxins like Botox and tetanus?
Vesicles cannot fuse with the membrane
What is the consequence of impaired vesicle recycling in genetic illnesses like congenital myasthenia syndromes?
Synaptic communication is compromised
What is the role of calcium ions in synaptic transmission?
Calcium ions trigger the release of neurotransmitter from vesicles
What is the main function of neuromodulators in synaptic transmission?
Neuromodulators change the ability of the postsynaptic cell to respond to other signals
What are the criteria for defining a neurotransmitter?
It needs to be synthesised in the neurons
What happens to neurotransmitter after it has served its purpose in synaptic transmission?
It is immediately removed from the synaptic cleft
Which of the following is NOT a component of a chemical synapse?
Cytoskeleton
What is the role of the synaptic cleft?
To allow neurotransmitter diffusion and binding to postsynaptic receptors
What is the main difference between the postsynaptic density and the motor end plate?
The motor end plate contains neurotransmitter receptors, while the postsynaptic density does not
Which of the following is true about the study of the neuromuscular junction?
It has provided a good model for studying synaptic transmission
Which of the following is NOT a function of transporters in synaptic transmission?
Releasing neurotransmitter molecules into the glial cells
What is the role of proton gradient in loading GABA into vesicles?
It provides energy for the process
What molecules can be transported by the transporters mentioned in the text?
Amino acids, alcohol, and neurotransmitters
What is the site of action for drugs that can affect synaptic transmission?
Transporters
What powers the loading of GABA molecules into vesicles?
Proton gradient
What is the function of transporters in synaptic transmission?
To load neurotransmitter molecules into vesicles
What is NOT a criteria that defines a neurotransmitter?
a specific mechanism exists for keeping it in the synaptic cleft
What is NOT a disease mechanism that affects the presynaptic terminal?
Latrotoxin triggers vesicle release
What kind of transporters are powered by proton gradient ATPase proton pump loads up vesicles with H+ making vesicles acidic (pH5.5) compared to neutral pH of cytoplasm (pH7.2)e.g. 1 glutamate traded for 1 H+ (counter-transport mechanism)
Vesicular transporters
What kind of transporters are powered by electrochemical gradient[Na+] higher outside / [K+] higher inside Glutamate co-transported with 2 Na+
Plasma membrane transporters
The tetanus toxin inhibits the release of neurotransmitters of which cells? Select the single best answer from the list below.
Inhibitory interneurons at the spinal cord
Study Notes
Synaptic Transmission and Neurotransmitters
- Synaptic transmission is the process by which information is passed from one neuron to another or to an effector organ, such as muscles and glands, at chemical synapses.
- There are three general categories of synapses: chemical synapses, electrical synapses, and tripartite synapses.
- Chemical synapses are the majority in the central nervous system (CNS) and involve the release of neurotransmitters.
- Chemical synapses can be classified based on their location, such as axodendritic, axosomatic, and axoaxonic synapses.
- The structure of a chemical synapse includes the presynaptic terminal, synaptic vesicles, active zone, synaptic cleft, and postsynaptic membrane.
- At the neuromuscular junction, an action potential reaching the presynaptic terminal triggers the release of neurotransmitter molecules, which then bind to receptors on the postsynaptic membrane and initiate a response.
- Neurotransmitters are synthesized in neurons, present in presynaptic terminals, and released in amounts sufficient to exert a defined effect on the postsynaptic neuron or effector organ.
- Botox and Tetanus toxins are examples of toxins that affect neurotransmitter release, causing muscle relaxation or permanent muscle contraction, respectively.
- Glia, or glial cells, play a crucial role in regulating synaptic connectivity and have various functions in synaptic transmission.
- Synaptic transmission relies on the release, recovery, and degradation of neurotransmitters, which are transported by membrane transporters.
- Glia also have involvement in diseases such as brain cancer, HIV-induced dementia, depression, and neurodegenerative diseases.
- Understanding synaptic transmission and neurotransmitters is important for understanding how neurons communicate and for the development of drugs that target synapses.
Test your knowledge of synaptic transmission with this quiz! Learn about the definition and types of synapses, neurotransmitters, and the differences between chemical synapses in the CNS and at the neuromuscular junction.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
