Neurology

• What is the main focus of Lecture 2 in the course BI2524?

  Signalling and communication
• What is the role of electrical activity in neurons?

  Firing of neurons due to action potential changes
• What is resting membrane potential?


  Membrane potential when cells are at rest
• What is the typical resting membrane potential in neurons?

  -60mV to -70mV
• What does the Goldman-Hodgkin-Katz (GHK) equation describe?

  Electrical potential difference across a barrier
• What factors determine the membrane potential according to the GHK equation?

  Ionic composition and permeability ratios
• What are voltage-gated ion channels?

  Channels that open or close with membrane potential changes
• What is the function of voltage-activated Na⁺ channels?

  Generate action potentials
• What is the role of voltage-activated K⁺ channels?

  Determine and restore resting membrane potential
• What do voltage-gated Ca²⁺ channels do?

  Transmit signals between cells
• How are action potentials triggered in neurons?

  By all-or-none electrical responses in the membrane
• What is the mechanism of action potentials?

  Rapid depolarization, polarity reversal, and repolarization
• What is the significance of axon size and insulation?

  Determines the speed of action potential propagation
• How do larger axons affect action potential propagation?

  They propagate action potentials faster
• What is myelin and its role?

  Electrical insulation that speeds up action potentials
• What is the composition of myelin?

  80% lipids and 20% proteins
• What is the Node of Ranvier?

  Gaps in myelin where action potentials are generated
• What is saltatory conduction?

  Action potentials jumping between Nodes of Ranvier
• How does myelination affect energy costs?

  Reduces energetic costs for signal transmission
• What are non-spiking neurons?

  Neurons that signal over short distances
• How do synapses function in neural communication?

  Transmit signals between neurons chemically or electrically
• What are the two types of synapses?

  Electrical synapses and chemical synapses
• What characterizes electrical synapses?

  Membranes of two cells are closely aligned
• How do chemical synapses transmit signals?

  Via chemical transmitter molecules between cells
• What is the role of connexons in electrical synapses?

  Form nonselective channels for ion passage
• What happens at the presynaptic membrane during signal transmission?

  Electric potential converts to a secretory process
• What triggers the release of transmitter molecules?

  Calcium-ion dependent release in the synaptic cleft
• What is synaptotagmin's role in neurotransmitter release?

  Calcium ion-sensitive switch for vesicle fusion
• What are ligand-gated channels?

  Channels that open when neurotransmitters bind
• What are metabotropic receptors?

  Receptors coupled to GTP-binding proteins
• What criteria define a neurotransmitter?

  Present in presynaptic terminal and released upon activation
• What is acetylcholine's role in the nervous system?

  Between autonomic neurons and skeletal muscles
• What types of receptors does acetylcholine bind to?

  Ionotropic and metabotropic receptors
• What is the role of noradrenaline and adrenaline?

  Both excitatory and inhibitory in the nervous system
• How is noradrenaline converted?

  Converted from dopamine
• What is serotonin's primary function in the nervous system?

  Mainly inhibitory in vertebrates
• What is the significance of selective serotonin reuptake inhibitors (SSRIs)?

  Widely used type of antidepressant
• What is dopamine's role in the nervous system?

  Both inhibitory and excitatory synapses
• What is histamine's role in the nervous system?

  Both inhibitory and excitatory synapses
• What is L-glutamate's significance in the brain?

  Most prevalent neurotransmitter in excitatory synapses