https://xcpsych.com/psychology/neurobiology/module-1/Module 1 - Neural signallingHugoBlox Kit (https://hugoblox.com)en-usMon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/cover.pnghttps://xcpsych.com/psychology/neurobiology/module-1/https://xcpsych.com/psychology/neurobiology/module-1/09-ion-pumps/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/09-ion-pumps/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/Lb_RVIvGVPw?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>If ions keep moving through channels, how do neurons maintain their concentration gradients?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>What ion pumps are</li> <li>How pumps differ from ion channels</li> <li>Why active transport requires energy</li> <li>How ATP powers ion transport</li> <li>What the sodium-potassium pump does</li> <li>Why ion gradients must be continuously maintained</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>Ion channels allow ions to move according to existing electrochemical gradients.</p> <p>Ion pumps use energy to maintain those gradients.</p> <p>Without those maintained differences, neurons would eventually lose the conditions required for electrical signalling.</p> <h2 id="module-takeaway">Module Takeaway</h2> <p>Neural signalling depends on a coordinated system:</p> <p><strong>ion gradients → membrane potential → action potentials → propagation → synaptic transmission</strong></p> <p>Channels allow ions to move.</p> <p>Pumps maintain the gradients that make that movement meaningful.</p>https://xcpsych.com/psychology/neurobiology/module-1/08-ion-channels/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/08-ion-channels/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/KJC2h4wlzeE?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>If ions cannot freely cross the cell membrane, how do they move through it?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>What ion channels are</li> <li>Why cell membranes are selectively permeable</li> <li>How channels can be selective for particular ions</li> <li>The difference between leak and gated channels</li> <li>How voltage-gated and ligand-gated channels work</li> <li>Why ion channels are essential for electrical signalling</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>Ion channels are proteins that provide selective pathways through the membrane.</p> <p>Opening and closing these pathways changes which ions can move and therefore changes membrane voltage.</p> <h2 id="next">Next</h2> <p>Continue to <strong>What Are Ion Pumps?</strong></p>https://xcpsych.com/psychology/neurobiology/module-1/07-neuron-decides-to-fire/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/07-neuron-decides-to-fire/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/CYGJlVAZFU4?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>How does a neuron decide whether to generate an action potential?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>What excitatory inputs do</li> <li>What inhibitory inputs do</li> <li>What spatial summation is</li> <li>What temporal summation is</li> <li>What threshold means</li> <li>How the axon initial segment integrates incoming signals</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>A neuron does not respond to a single input in isolation.</p> <p>It integrates many excitatory and inhibitory influences, and an action potential occurs when membrane voltage reaches threshold.</p> <h2 id="next">Next</h2> <p>Continue to <strong>What Are Ion Channels?</strong></p>https://xcpsych.com/psychology/neurobiology/module-1/06-electricity-to-chemistry/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/06-electricity-to-chemistry/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/YOMNrdWz1AA?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>How does an electrical signal inside one neuron become a chemical signal between neurons?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>What happens when an action potential reaches the axon terminal</li> <li>Why calcium channels open</li> <li>How calcium triggers neurotransmitter release</li> <li>What synaptic vesicles do</li> <li>How neurotransmitters cross the synaptic cleft</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>At the axon terminal, an electrical signal triggers calcium entry.</p> <p>Calcium then helps trigger neurotransmitter release, converting electrical signalling into chemical communication.</p> <h2 id="next">Next</h2> <p>Continue to <strong>How Does a Neuron Decide to Fire? ⚖️</strong></p>https://xcpsych.com/psychology/neurobiology/module-1/05-myelin/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/05-myelin/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/23jfehX9Mlc?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>Why does myelin make neuronal signalling so much faster?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>What myelin is</li> <li>How myelin electrically insulates the axon</li> <li>What nodes of Ranvier are</li> <li>What saltatory conduction means</li> <li>Why myelinated axons transmit signals efficiently</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>Myelin reduces current loss across the axonal membrane and allows action potentials to be regenerated mainly at the nodes of Ranvier.</p> <p>The signal therefore appears to &ldquo;jump&rdquo; from node to node.</p> <h2 id="next">Next</h2> <p>Continue to <strong>How Does Electricity Become Chemistry?</strong></p>https://xcpsych.com/psychology/neurobiology/module-1/04-action-potential-direction/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/04-action-potential-direction/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/RirB3tueJ-8?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>If depolarisation spreads in both directions, why does the action potential normally move forward?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>What the absolute refractory period is</li> <li>What the relative refractory period is</li> <li>Why voltage-gated sodium channels become inactivated</li> <li>Why recently activated membrane cannot immediately fire again</li> <li>How refractory periods support one-way propagation</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>The membrane just behind an action potential is temporarily unable, or less able, to fire again.</p> <p>This refractory state makes forward propagation much more likely than backward propagation.</p> <h2 id="next">Next</h2> <p>Continue to <strong>Why Is Myelin Basically Biological Fibre Optic Cable?</strong></p>https://xcpsych.com/psychology/neurobiology/module-1/03-axon-signal/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/03-axon-signal/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/4JUuNShweZI?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>When a neuron fires, what actually travels down the axon?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>What an action potential is</li> <li>Why individual ions do not travel from one end of the axon to the other</li> <li>How one region of membrane influences the next</li> <li>How depolarisation propagates along an axon</li> <li>Why the process resembles a relay</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>An action potential is not a group of ions racing down the entire axon.</p> <p>Instead, changes in membrane voltage trigger neighbouring regions of membrane in sequence.</p> <h2 id="next">Next</h2> <p>Continue to <strong>Why Doesn&rsquo;t the Action Potential Go Backwards?</strong></p>https://xcpsych.com/psychology/neurobiology/module-1/02-physics-and-wind/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/02-physics-and-wind/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/CMaB4n17xpM?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>What can physics — and even wind — teach us about neuronal signalling?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>How gradients create tendencies for movement</li> <li>Why differences in energy or concentration matter</li> <li>How physical forces influence particles</li> <li>Why ions move according to more than one force</li> <li>How these ideas connect to neurons</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>Movement often occurs because there is a difference between two places.</p> <p>In neurons, differences in concentration and electrical charge create forces that influence ion movement.</p> <h2 id="next">Next</h2> <p>Continue to <strong>What Really Travels Down the Axon?</strong></p>https://xcpsych.com/psychology/neurobiology/module-1/01-potential/Mon, 24 Aug 2026 00:00:00 +0000https://xcpsych.com/psychology/neurobiology/module-1/01-potential/<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"> <iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share; fullscreen" loading="eager" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/ffMhf4McsV8?autoplay=0&amp;controls=1&amp;end=0&amp;loop=0&amp;mute=0&amp;start=0" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" title="YouTube video"></iframe> </div> <h2 id="key-question">Key Question</h2> <p>Why do we call it electrical <strong>potential</strong>?</p> <h2 id="what-youll-learn">What You&rsquo;ll Learn</h2> <ul> <li>What electrical potential means</li> <li>How electrical potential relates to energy</li> <li>What voltage measures</li> <li>Why separating charges creates electrical potential</li> <li>Why membrane potential matters in neurons</li> </ul> <h2 id="key-takeaway">Key Takeaway</h2> <p>Electrical potential describes the ability of separated charges to do work.</p> <p>A neuron&rsquo;s membrane potential reflects a difference in electrical potential across the cell membrane.</p> <h2 id="next">Next</h2> <p>Continue to <strong>Some Physics and&hellip; Wind?</strong></p>