77 questions · 34 almanac · 1 findings

Neuron Physiology and Signaling

How individual neurons generate and transmit signals.

Almanac A Net, or Separate Threads?
  • What was the central disagreement between the neuron doctrine and the reticular theory of the nervous system?
  • How did Cajal use Golgi's own staining technique to argue against Golgi's theory of a continuous nerve network?
  • Why was the 1906 joint Nobel Prize to Golgi and Cajal considered an awkward pairing?
Almanac Two Men, One Stain, Opposite Conclusions
  • What did Camillo Golgi's silver-staining technique allow scientists to see for the first time?
  • How did Santiago Ramón y Cajal use Golgi's own staining method to argue against Golgi's reticular theory?
  • What is the difference between the reticular theory and the neuron doctrine of the nervous system?
  • Why did the two Nobel laureates use their acceptance lectures to publicly disagree with each other?
Almanac The Nerve That Speaks in Pulses
  • What did Edgar Adrian discover about how nerve fibres encode signal strength?
  • How did Sherrington and Adrian's work reframe the neuron as an active computational unit rather than a passive wire?
Almanac Catching a Thought Mid-Spike
  • What technical advance in the 1920s finally made it possible to record a single nerve fibre instead of a smeared average?
  • What did Edgar Adrian's earlier Nobel-winning work show about how nerve impulses are structured?
  • How does the action potential propagate along a neuron once triggered?
  • What did Hodgkin and Huxley later discover about the role of sodium and potassium ions in generating the nerve spike?
Almanac Gaps Between Cells, Drawn From Memory
  • How did Cajal's drawings of neurons prove that the nervous system was made of discrete cells rather than a continuous web?
  • Why did Cajal and Camillo Golgi share the 1906 Nobel Prize despite holding opposite views on nerve structure?
  • How accurate have Cajal's hand-drawn neuron illustrations turned out to be compared to modern electron microscopy?
Almanac A Chemical Message, Dreamed Twice
  • What experiment did Otto Loewi run on two frog hearts to prove nerve signals are chemical rather than purely electrical?
  • How did Loewi's dream on Easter Saturday 1921 lead directly to a testable experiment?
  • What role did Henry Dale play in identifying acetylcholine and mapping the neurotransmitter system?
  • Which modern drug classes work by altering the chemical signalling between nerves that Loewi and Dale discovered?
Almanac Pain Travels on Separate Wires
  • How did Erlanger and Gasser use oscilloscope technology to disprove the idea that a nerve acts like a single wire?
  • Why do thick, myelinated nerve fibres conduct signals so much faster than thin, unmyelinated ones?
  • What explains the two-part sensation of a quick sharp 'ouch' followed later by a deeper ache from the same injury?
Almanac A Conductor No One Had Noticed
  • What range of bodily functions did Hess's electrode-stimulation experiments reveal were coordinated by this brain region?
Almanac A Squid's Nerve Writes Its Own Equations
  • Why did Hodgkin and Huxley use the giant axon of a squid for their nerve impulse experiments?
  • What do the Hodgkin-Huxley equations describe about sodium and potassium ion flow during an action potential?
  • What did John Eccles discover about whether synaptic transmission is chemical or electrical?
Almanac Edges Sharpened Before You Notice
  • What did Hartline's horseshoe crab experiments reveal about lateral inhibition between photoreceptors?
  • How does the retina's edge-sharpening mechanism resemble the sharpening filters used in modern photo editing?
Almanac How a Nerve Signal Switches Itself Off
  • What did Bernard Katz mean by showing that acetylcholine release at the neuromuscular junction is 'quantal'?
  • What role does noradrenaline play in the sympathetic nervous system, according to Ulf von Euler's work?
  • How did Julius Axelrod's discovery of noradrenaline re-uptake lead to modern antidepressant drugs?
  • Why does blocking a neurotransmitter transporter make that neurotransmitter linger longer in the synapse?
Almanac Two Minds Under One Skull
  • How did Hubel and Wiesel discover that visual cortex neurons respond to specific features like edges and angles?
Almanac A Glass Pipette Hears One Channel Open
  • How does the patch-clamp technique isolate the electrical signal of a single ion channel?
  • Why was it previously impossible to observe individual ion channels rather than population averages?
Almanac A Molecular Shaft That Spins to Make Fuel
  • What does the sodium-potassium pump do for a nerve cell, and why was it such a significant find?
  • Why were two unrelated discoveries about cellular energy and ion transport awarded the same prize?
Almanac Seeing the Filter That Sorts Potassium From Sodium
  • How did Armstrong and Hille use electrophysiology to map ion channel behaviour before anyone could see the channels?
  • What did Roderick MacKinnon's crystallised potassium channel structure reveal that electrical measurements alone could not?
  • How does a potassium channel's selectivity filter distinguish potassium ions from similarly sized sodium ions?
Almanac Breeding the Heat Out of a Jalapeño
  • Why does capsaicin deter mammals from eating peppers while leaving birds unaffected?
  • How did Paul Bosland selectively breed capsaicin out of the jalapeño while keeping its shape and flavour?
  • What makes removing a dominant trait like capsaicin production a multi-generation breeding challenge?
Almanac How a Grandfather Buttons His Shirt Again
  • What did Arvid Carlsson prove about dopamine that overturned earlier assumptions?
  • How does L-DOPA therapy restore movement to Parkinson's patients?
  • What did Paul Greengard discover about how slow-acting neurotransmitters signal cells?
  • How did Eric Kandel use the sea slug Aplysia to explain short-term versus long-term memory?
Almanac Love Looks Like a Disorder, Chemically
  • What did Marazziti's study compare between newly infatuated people and OCD patients?
  • What did the serotonin transporter levels reveal about people newly in love?
  • How did the newly infatuated group's results differ from people in long-term relationships?
Almanac Water Crosses the Membrane in Single File
  • How does a potassium channel achieve ten-thousand-to-one selectivity over sodium ions that are barely smaller?
  • What role does the selectivity filter's geometry play in how neurons fire?
Almanac A Full Bladder Sharpens Some Judgment
  • How does needing to urinate affect a person's risk tolerance and self-control?
  • What is inhibitory spillover, and how does it explain the bladder-decision-making link?
Almanac A Trigger Held in Hair-Trigger Readiness
  • What synaptic vesicle proteins did Richard Scheller identify as the core of the docking and fusion apparatus?
  • How does calcium binding to synaptotagmin trigger the final fusion step of neurotransmitter release?
  • Why does neurotransmitter release need to happen in under a millisecond, and what machinery makes that speed possible?
Almanac A Suggestion, Not a Law
  • What kinds of cellular structures became visible for the first time once super-resolution microscopy existed?
Almanac Orgasm Beats the Decongestant, Briefly
  • How long did nasal relief from orgasm last compared to a decongestant spray?
  • What physiological mechanism explains why orgasm relieves nasal congestion?
Almanac Pink Salt Flats to a Switch for Neurons
  • How do channelrhodopsins let green algae steer toward or away from light?
  • How did Karl Deisseroth combine these microbial proteins to switch neurons on and off with light?
Almanac The Flesh Has Proteins Shaped for Feeling
  • How did David Julius use capsaicin to identify the receptor for heat, TRPV1?
  • Why does TRPV1 make spicy food and high heat feel like the same sensation?
  • What experimental method did Patapoutian use to discover the Piezo1 and Piezo2 channels?
  • How do Piezo channels give the body its sense of touch and proprioception?
Almanac A Breathalyser for Worms
  • Why does C. elegans' simple, well-mapped nervous system make it useful for studying how ethanol affects neurons?
Finding Deep Learning for Cognitive Neuroscience
  • What does scaling from principles and circuit models to complex end-to-end trainable systems reveal about how the brain manages information processing demands?