Topic 99 - Axonal transport and synaptic transmission, sensors, types of ion channels Flashcards
1
Q
Words to include in axonal transport and synaptic transmission
A
- Axonal transport
- Neuropeptide
- Vesicles
- Presynaptic nerve ending
- Neuro peptides (binding)
- Modulated peptides (binding)
- Carrier proteins
- Action potential
- Axon
- Synaptic nerve ending
- Neurotransmitters
- Norepinephrine / noradrenaline
- Acetylcholine
- Glicin
- Larger peptides
- Synthesis
- Peptides
- Vesicles
- Soma
- Neuron
- Motor proteins / transporter
- ATP
- Microtubular system
- Anterograde transport
- Soma → nerve ending
- Kinesin
- Retrograde transport
- Nerve ending → soma
- Dynein
- Synaptic cleft
- Postsynaptic membrane
- Hyperpolarization
- Resting membrane potential ↑
- Depolarization
- Resting membrane potential ↓
Neural network
- Neural network
- Synapse
- Neuron
- Axon
- Soma
- dendrite
- Neuron
- CNS
- Neurons
- Electrical synapse
- Presynaptic neurons
- Postsynaptic neurons
- Gap junction
- Fast response
- Defensive reflexes
- Bidirectional
- Gap junction
- Synapse
- Free diffusion of charges
- Connexin
- Hexamer
- 6 connexin peptide
- Hydrophilic channel
- Fast communication
- Bidirectional
- Rectification
- CNS
- Fast reflex arches
- Cardiac cells
- Chemical synapse
- Junctions
- Non-neuronal cells
- Vesicles
- Exocytosis
- Postsynaptic cell side
- Threshold action potential
- Presynaptic terminal
- Post-synaptic density
- Voltage gated Ca2+ channel
- Synaptic vesicle
- Axon terminal
- Neurotransmitters
- Neurotransmitter re-uptake pump
- Neurotransmitter receptors
- Synaptic cleft
- Dendritic spine
- Metabotropic effect
- Neurotransmitter
- Receptor
- Postsynaptic neuron
- Short term change
- Long term change
- EPSP (Excitatory Postsynaptic Potential)
- Postsynaptic neuron (↑)
- IPSP (Inhibitory Postsynaptic Potential)
- Postsynaptic neuron (↓)
2
Q
Words to include in sensors, types of ion channels
A
- Na+
- K+
- Cl-
- Leaking Na+, K+ and Cl- channels
- Membrane potential
- Voltage dependent Na+ and K+ channels
- Action potential
- Ligand dependent non-selective Na+, K+ and Cl- channels
- Mechanoreceptive
- Mechanical stimuli
- Energy sensor
- K+ channe
- ATP
- Depolarization
- ATP concentration
- Voltage dependent Na+ channel
- Protein
- IC part
- Transmembrane part
- EC part
- 6-6 transmembrane segments
- Tetrodotoxin (TIX)
- Ligand dependent ion channel
- Nicotinic acetylcholine (n-ACh)
- Nicotine
- Curare
- Neuro-muscular junction
- CNS
- Skeletal muscle
- Pentamer
- 2 α subunit
- 2 β subunit
- 1 Δ subunit
- D-tubocurarine
- Pentamer
- Nervous system
- 2 α subunit
- 3 β subunit
- Glutamate
- Excitatory system
- CNS
- Permable
- Na+
- K+
- Ca2+
- AMPA
- NMDA
- Kainate
- Anion channels
- Hyperpolarization
- Mediators
- GABA
- Glycine
- G-protein mediated
- Nicotinic acetylcholine (n-ACh)
- Mechanoreceptive channels (Ca2+-ion channels)
- Ryanodine and DHP
- Voltage sensors
- T-tubules
- Triad
- Dihydropyridine (DPH)
- Ca2+-channels
- Ryanodine
- Sarcoplasmic reticulum (SR)
- IP3-receptor
- IC Ca2+ stores
- Voltage-dependent
- P-type calcium channel
- T-type calcium channel
- N-type calcium channel
- Ryanodine and DHP
- Energy sensor ion channel
- ATP
- Regulator subunit
- Pore-forming subunit
- Conformational change
- K+ efflux
- Depolarization
- Ca2+ influx
3
Q
Topics to include in the essay
A
- Axonal transport
- Neural network
- Synapse
- Electrical synapse
- Gap junction
- Chemical synapse
- Metabotropic effect
- Synapse
- Sensors, types of ion channels
- Voltage dependent Na+ channel
- Ligand-dependent ion channel
- n-ACh
- Glutamate
- Anion channels
- G-protein mediated
- Mechanoreceptive channels (Ca2+ ion channels)
- Ryanodine & DHP
- IP3-receptor
- Voltage-dependent
- Energy sensor ion channel
4
Q
Axonal transport
A
- The action potential - conducted through the axon in the synaptic nerve ending produces the release of neurotransmitters
- The synthesis of peptides and vesicles is only possible in the soma of the neuron
- Axonal transport: The produced neuropeptides and vesicles must be transported to the presynaptic nerve ending
- Molecular base of the transport: the binding of the neuro- and modulator peptides to carrier proteins in the soma
- These transporter or motor proteins uses ATP on the microtubular system along the axis of the axon
- Soma → nerve ending: Anterograde transport by kinesin
- Nerve ending → soma: Retrograde transport by dynein
- Vesicles stored in nerve endings are released to the synaptic cleft as a result of an action potential
- The neurotransmitter can bind to their specific receptors on the postsynaptic membrane
- The result of receptor-binding can be:
- Hyperpolarization: Resting membrane potential ↑
- Depolarization: Resting membrane potential ↓
5
Q
Axonal transport
What are neurotransmitters composed of?
A
- Small molecular weight substances, eg.:
- Norepinephrine
- Acetylcholine
- Glicin
- Large peptides
6
Q
Neural network
Define synapse
A
-
Synapse:
- Contact between the axon of one neuron and a dendrite or soma of another
- Allows neurons to from circuits within the CNS
- Allow the nervous system to connect to and control other systems of the body
7
Q
Neural network
Name the different type of synapse
A
- Electrical synapse
- Gap junction
- Chemical synapse
8
Q
Neural network
Synapse: Electrical synapse
A
- A mechanical and electrically conductive link between two neurons that is formed at a narrow gap between the pre- and postsynaptic neurons known as a gap junction
- Compared to chemical synapses:
- Electrical synapses conduct nerve impulses faster
- Unlike chemical synapses, they lack gain - the signal in the postsynaptic neuron is the same or smaller than that of the originating neuron
- Location: In neural systems that require the fastest possible response
- Eg. defensive reflexes
- Bidirectional (most of the time)
9
Q
Neural network
Synapse: Gap junction
A
- Allows free diffusion of charges between cells
-
Connexin:
- Hexamer
- Built up by six connexin peptide
- The shortest information transduction which allows the fastest communication between cells
-
Bidirectional
- Rectification: In some junctions one of the directions is dominant
- Location: fast reflex arches in the CNS
- Eg. between cardiac cells
10
Q
Neural network
Synapse: Chemical synapse
A
- Signal between:
- Between neurons
- Between neuron and non-neuronal cells
- One neuron releases neurotransmitter molecules into the synaptic cleft
- Triggered by a nerve impulse/AP
- The neurotransmitters are kept within vesicles and are released into the synaptic cleft by exocytosis. These molecules then bind to receptors on the postsynaptic cell’s side of the synaptic cleft
- In response to a threshold action potential, a neurotransmitter is released at the presynaptic terminal
11
Q
Metabotropic effect
A
- Metabotropic effect: The binding of neurotransmitters to receptors in the postsynaptic neuron can trigger either short term changes or long term changes
- Long term effects are based on the the fact that neurotransmitters cause intramembrane or IC changes leading to long term depolarization or hyperpolarization
- Metabolic changes evokes the alteration of K+ and Ca2+ conductance, which is the primary reasons of long term depolarization or hyperpolarization
-
Gap junction procces leads either to:
-
EPSP (Excitatory Postsynaptic Potential)
- Man discharge frequency of the postsynaptic neuron ↑
-
IPSP (Inhibitory Postsynaptic Potential)
- Man discharge frequency of the postsynaptic neuron ↓
-
EPSP (Excitatory Postsynaptic Potential)
- Transmitters involved: Metabotropic transmitters
- Response to them: metabotropic response
- Binding of ligand to receptor
- IC 2nd messenger
- IC metabolic (metabotropic) effect
- Long lasting depolarization or hyperpolarization
12
Q
Types of ion channels
Role
A
- They are proteins molecules that span across the cell membrane allowing the passage of ions from one side of the membrane to the other side
- They are selective - they only allow certain ions to pass
- They are involved in the transmission of signals in the nervous system
13
Q
Type of ion channels
Name the different types of ion channels
A
-
Leaking sodium, potassium and chloride channels
- Maintenance of the membrane potential
-
Voltage-dependent sodium and potassium channels
- Generation of action potential
-
Ligand-dependent non-selective sodium, potassium and chloride channels
- Multiple
-
Mechanoreceptive
- Uptake of tactile and other mechanical stimuli
-
Energy sensor
- Potassium channel sensitive to ATP causes depolarization according to the ATP concentration of cell
- More info about these channels on the next cards:
- Voltage dependent Na+ channel
-
Ligand dependent ion channels
- Nicotinic acetylcholine dependent non-selective Na+/K+ channel
- Glutamate dependent cation channel
- Anion channels
- G-protein mediated signal transduction
-
Mechanoreceptive channels (Ca2+ ion channels)
- Ryanodine and DHP
- IP3-receptor
- Voltage-dependent
- Energy sensor ion channel
14
Q
Types of ion channels
Voltage dependent Na channel
A
- This protein contains IC, transmembrane and EC parts
- Four main domains with 6-6 transmembrane segments (1-6) each
- Specific inhibitor: tetrodotoxin (TIX, a poison)
15
Q
Types of ion channels
Name the different types of ligand dependent ion channels
A
- Nicotinic acetylcholine dependent non-selective Na+/K+ channel
- Glutamate dependent cation channels
- Anion channels
- G-protein mediated signal transduction