Chapter 5_Signaling Between Neurons Flashcards
Electrical synapses
Synapses where electrical signals pass directly from one neuron to another through gap junctions, allowing for rapid signal transmission.
Chemical synapses
Synapses where neurotransmitters are released from one neuron and bind to receptors on another neuron, allowing for slower, but more modifiable, signal transmission.
Connexons
Protein channels that form gap junctions in electrical synapses, allowing ions and small molecules to pass directly between cells.
Synaptic vesicles
Membrane-bound sacs in the presynaptic neuron that store neurotransmitters and release them into the synaptic cleft upon receiving an action potential.
Neurotransmitters
Chemical substances released by neurons at synapses that transmit signals to other neurons, muscle cells, or gland cells.
Synaptic cleft
The small gap between the presynaptic and postsynaptic neurons at a chemical synapse, across which neurotransmitters diffuse to transmit a signal.
Ionotropic receptors
Receptors that directly control an ion channel when a neurotransmitter binds to them, resulting in rapid changes in the postsynaptic cell’s membrane potential.
Metabotropic receptors
Receptors that indirectly influence ion channels through the activation of second messengers when a neurotransmitter binds to them, leading to slower but more prolonged effects on the postsynaptic cell.
Exocytosis
The process by which synaptic vesicles fuse with the presynaptic membrane to release neurotransmitters into the synaptic cleft.
Endocytosis
The process by which a cell takes in materials from the outside by engulfing and fusing them with its plasma membrane, often used by neurons to retrieve synaptic vesicle membrane after neurotransmitter release.
Synaptic plasticity
The ability of synapses to strengthen or weaken over time, in response to increases or decreases in their activity, which is crucial for learning and memory.
Retrograde signaling
Communication that travels from the postsynaptic neuron back to the presynaptic neuron, often involving signaling molecules like endocannabinoids.
Endocannabinoids
Lipid-based neurotransmitters that bind to cannabinoid receptors and can modulate neurotransmitter release, involved in retrograde signaling.
GABA (gamma-aminobutyric acid)
The primary inhibitory neurotransmitter in the central nervous system, which reduces neuronal excitability.
Glutamate
The primary excitatory neurotransmitter in the central nervous system, involved in most aspects of normal brain function including cognition, memory, and learning.
Acetylcholine
A neurotransmitter involved in muscle activation, attention, and arousal.
Dopamine
A neurotransmitter involved in reward, motivation, and motor control, with dysfunctions linked to conditions like Parkinson’s disease and schizophrenia.
Serotonin
A neurotransmitter that affects mood, appetite, and sleep, with dysregulation associated with depression and anxiety disorders.
Norepinephrine
A neurotransmitter involved in arousal and alertness, also known as noradrenaline.
Neuropeptides
Large protein-like molecules used by neurons to communicate with each other, influencing the activity of the brain and body in specific ways.
Nitric oxide (NO)
A gaseous neurotransmitter involved in various neural processes, including vasodilation and synaptic plasticity.
Botulinum toxin
A neurotoxin produced by the bacterium Clostridium botulinum, which inhibits acetylcholine release and causes paralysis.
Synaptotagmin
A calcium-binding protein that plays a key role in triggering neurotransmitter release at synapses.
SNARE proteins
A family of proteins that mediate the fusion of synaptic vesicles with the presynaptic membrane to release neurotransmitters.
Reuptake
The process by which neurotransmitters are taken back into the presynaptic neuron after they have been released into the synaptic cleft, terminating the signal.
Selective serotonin reuptake inhibitors (SSRIs)
A class of drugs used to treat depression and anxiety by inhibiting the reuptake of serotonin, increasing its levels in the synaptic cleft.
Gap junction
Specialized intercellular connections that allow direct electrical communication between adjacent cells, facilitating rapid signal transmission.
Charcot-Marie-Tooth (CMT) disease
A hereditary disorder that affects the peripheral nerves, leading to muscle weakness and atrophy.
Presynaptic neuron
The neuron that releases neurotransmitters into the synapse.
Postsynaptic neuron
The neuron that receives neurotransmitters from the presynaptic neuron.
Receptor
A protein molecule that receives and responds to a neurotransmitter or hormone.
Neuromuscular junction
The synapse between a motor neuron and a muscle fiber, where acetylcholine is released to trigger muscle contraction.
Small vesicles
Synaptic vesicles that contain classical neurotransmitters and are released in response to low-frequency stimulation.
Large dense-core vesicles
Vesicles that contain neuropeptides and are released in response to high-frequency stimulation.
Electron microscopy
A technique that uses a beam of electrons to create an image of a specimen, allowing for very high resolution and magnification.
Vesicular GABA transporters (VGAT)
Transport proteins that load GABA into synaptic vesicles.
Vesicular glutamate transporters (VGluT)
Transport proteins that load glutamate into synaptic vesicles.
Vesicular acetylcholine transporter (VAChT)
Transport proteins that load acetylcholine into synaptic vesicles.
Vesicular monoamine transporters (VMATs)
Transport proteins that load monoamines (dopamine, norepinephrine, serotonin) into synaptic vesicles.
Vesicular ATP-ase
An enzyme that provides the energy for loading neurotransmitters into synaptic vesicles.
Antiporters
Transport proteins that move two different molecules or ions across a membrane in opposite directions.
Readily releasable pool (RRP) vesicles
Synaptic vesicles that are docked at the presynaptic membrane and ready to release neurotransmitters upon stimulation.
Recycling pool vesicles
Synaptic vesicles that are available for release but are not docked at the presynaptic membrane.
Reserve pool vesicles
Synaptic vesicles that are stored away from the presynaptic membrane and are only used during high-frequency stimulation.
V-SNAREs
SNARE proteins located on synaptic vesicles that are involved in vesicle docking and fusion.
T-SNAREs
SNARE proteins located on the presynaptic membrane that are involved in vesicle docking and fusion.
Botulism
A rare but serious illness caused by a toxin that attacks the body’s nerves, leading to muscle paralysis.
Voltage-gated calcium channels
Ion channels that open in response to depolarization and allow calcium ions to enter the cell, triggering neurotransmitter release.
Full fusion
A mechanism of neurotransmitter release where the vesicle membrane completely merges with the presynaptic membrane.
Kiss-and-run
A mechanism of neurotransmitter release where the vesicle briefly contacts the presynaptic membrane and releases its contents before detaching.
SNARE complex
A complex of SNARE proteins that mediates the fusion of synaptic vesicles with the presynaptic membrane.
Active site
The region of a receptor or enzyme where the binding of a neurotransmitter or substrate occurs.
Orthosteric site
The primary site on a receptor where a neurotransmitter or drug binds to exert its effect.
Ligands
Molecules that bind to specific receptors to exert their biological effects.
Ligand-gated ion channels
Ion channels that open in response to the binding of specific molecules (ligands) such as neurotransmitters.
G proteins
Guanine nucleotide-binding proteins that transmit signals from receptors to target enzymes or ion channels inside the cell.
G protein-coupled receptors (GPCRs)
A large family of receptors that interact with G proteins to transmit signals inside the cell.
Presynaptic receptors
Receptors located on the presynaptic neuron that modulate neurotransmitter release.
Autoreceptors
Presynaptic receptors that respond to the neurotransmitter released by the same neuron, providing feedback regulation.
Excitotoxicity
A pathological process where neurons are damaged and killed by excessive stimulation by neurotransmitters such as glutamate.
Glycine
An inhibitory neurotransmitter in the central nervous system, particularly in the spinal cord.
Dopamine (DA)
A neurotransmitter involved in reward, motivation, and motor control.
Ventral tegmental area (VTA)
A part of the brain involved in the reward system and the release of dopamine.
Substantia nigra
A part of the brain that plays an important role in reward and movement, contains dopaminergic neurons.
D1 and D5 receptors
Subtypes of dopamine receptors that are typically excitatory.
D2, D3, and D4 receptors
Subtypes of dopamine receptors that are typically inhibitory.
Serotonin (5-HT)
A neurotransmitter that affects mood, appetite, and sleep.
Raphe nucleus
A cluster of nuclei in the brainstem involved in the release of serotonin.
5-HT2A receptor
A subtype of serotonin receptor involved in various neural processes, including mood regulation.
5-HT5 receptor
A subtype of serotonin receptor with various functions in the central nervous system.
5-HT3 receptor
A subtype of serotonin receptor that is a ligand-gated ion channel.
Fluoxetine
A selective serotonin reuptake inhibitor (SSRI) commonly used to treat depression and anxiety.
Parkinson’s disease (PD)
A neurodegenerative disorder characterized by the death of dopaminergic neurons in the substantia nigra, leading to motor control issues.
L-DOPA-induced dyskinesia (LID)
Involuntary movements that can result from long-term use of L-DOPA in the treatment of Parkinson’s disease.
Hyperkinesias
Abnormally increased muscle movements.
Deep brain stimulation
A surgical treatment for Parkinson’s disease and other conditions that involves implanting electrodes in the brain to modulate neural activity.
Acetylcholine (ACh)
A neurotransmitter involved in muscle activation, attention, and arousal.
Nicotinic acetylcholine receptors (nAChRs)
Ionotropic receptors for acetylcholine found in the central and peripheral nervous systems.
Norepinephrine (NE)
A neurotransmitter involved in arousal and alertness, also known as noradrenaline.
Beta blockers
Medications that block beta-adrenergic receptors, used to treat high blood pressure and other conditions.
Atypical neurotransmitters
Neurotransmitters that do not fit the classic definition, such as endocannabinoids and nitric oxide.
Enkephalin
A type of neuropeptide involved in regulating pain and reward.
Opioid receptors
Receptors that bind to opioid peptides and opiate drugs, involved in pain relief and reward.
Endocannabinoids (eCBs)
Lipid-based neurotransmitters that bind to cannabinoid receptors and can modulate neurotransmitter release.
CB1 receptors
Cannabinoid receptors primarily found in the brain and central nervous system.
CB2 receptors
Cannabinoid receptors primarily found in the peripheral nervous system and immune cells.
