Neural Signaling: Mechanisms and Pathways

This lesson explores the fundamental processes of neural signaling, including the structure and function of neurons, action potential generation, synaptic transmission, and neurotransmitter roles. Students will investigate how electrical and chemical signals facilitate communication within the nervous system and analyze real-world applications, such as neurodegenerative diseases and artificial neural networks. Through interactive discussions, demonstrations, and problem-solving activities, students will develop a deeper understanding of the nervous system’s role in regulating bodily functions and behavior.

1. Title of the lesson: C2.2 Neural signalling Facilitator Name: Pawan Kumar Guiding Question: • How are electrical signals generated and moved within neurons? • How can neurons interact with other cells? International-mindedness: How has global collaboration in neuroscience led to has led to groundbreaking medical advancements? Theory of Knowledge: To what extent does our understanding of the nervous system depend on the ways of knowing (such as reason, sense perception, and imagination)?

2. Learning Objective Write the learning objective for this lesson. Learning Outcomes List learning outcomes for this lesson ATL Skills – Research , communication & self-management Identify the type of skill and briefly outline how it will be achieved in this lesson Analyze the structure and function of neurons, explaining how the organization of the cell body, axon, and dendrites enables the transmission of electrical impulses. Evaluate the role of the sodium-potassium pump in generating resting potential, interpreting how ion movement establishes membrane polarization and maintains neuronal function. By the end of the lesson, students will be able to: Explain the structure of neurons and how their components (cell body, axon, dendrites) facilitate the conduction of electrical impulses. Demonstrate an understanding of the sodium-potassium pump by describing how ion movement generates resting potential and maintains membrane polarization. Students to use information literacy and media literacy to find information on International Mindedness prompt. Station learning in flexible groups (collaboration) on nerve impulse propagation.

3. Entry ticket(5mins): Explore Global Neuroscience Initiatives: Use the internet to research international neuroscience projects such as the Human Brain Project (EU), BRAIN Initiative (USA), and China Brain Project. Identify the goals of these projects and their contributions to medical advancements. Post your view on padlet and comment on 2 other peers response to voice your view on others perspective.(IM) Content(15 mins): Neuron structure, resting membrane potential, pumps and channels, potential difference Resource links: Flash cards venturing nervous system and neuron - Savemyexams C.2.2 Neural signalling SL/HL Topical notes (pg-5 neuron structure)- Savemyexams Video-neuron structure,pumps&channels , potential difference - Youtube Approach: Teacher led followed by Asynchronous exploration with differentiated & guided resources. Teacher moving around student clusters. Students will be differentiated into flexible groups and upon preliminary introduction by teacher the students would watch the video, interactive video or read from the document based on their comfort to prepare for a short reflection- “How is neuron able to generate a chemical gradient across its plasma membrane?”

4. Concept (15 minutes) : Analyze & demonstrate an understanding of the sodium-potassium pump by describing how ion movement generates resting potential and maintains membrane polarization. Resource links: Simulation Action potential Colorado-Boulder - PhET Approach: Teacher guided Exploration and Station learning-Student agency Key Terms List: Resting Potential, Threshold Potential, Depolarization, Repolarization, Hyperpolarization, Refractory Period, Sodium-Potassium Pump, Voltage-Gated Ion Channels, Na+ (Sodium Ions), K+ (Potassium Ions), Action Potential, Axon, Myelin Sheath, Nodes of Ranvier, Saltatory Conduction. Engaging Hook-task: Teacher guided asynchronous micro-session. Venture across the topical note pg-20 to 23 Watch video & collect anecdotal Simulate action potential.

5. STATION LEARNING: 20 MINUTES Station 1: Resting Potential – The Calm Before the Storm Objective: Understand how the neuron maintains a resting potential of -70mV through ion distribution. Student Task: Arrange the Na+ ions outside the axon membrane and K+ ions inside, ensuring more Na+ outside than inside. Use sticky notes to label the Na+ and K+ channels (some K+ channels remain open). Discuss: Why does the inside of the neuron remain negatively charged? How does the sodium-potassium pump maintain resting potential? What would happen if the Na+/K+ pump stopped working? Station 2: Depolarization – The Action Begins! Objective: Model the entry of Na+ ions and the generation of an action potential . Student Task: Apply a stimulus (touch the "Stimulus" marker). Open some Na+ channels (move a few Na+ ions inside). If the threshold (-50mV) is reached, open all Na+ channels and allow a flood of Na+ ions inside. Observe how the charge flips (inside becomes positive ~ +40mV). Pass Na+ ions down the axon, showing how depolarization travels like a wave. Station 3: Repolarization & Refractory Period – Resetting the System Objective: Model K+ ion movement to restore the resting state. Student Task: Close Na+ channels (label them "Inactive"). Open K+ channels, allowing K+ ions to exit the axon. Observe how the inside of the axon becomes negative again (~ -80mV). Briefly discuss the hyperpolarization phase and the refractory period (sticky notes marking "Refractory Period – No New Impulse"). Use the sodium-potassium pump to move Na+ back out and K+ back in, restoring resting potential.

6. Exit Ticket(5 minutes): Submission of Learning Transcripts: Each student writes a brief summary (3-5 sentences) explaining how an action potential is generated and propagated along a neuron. 2. ToK -To what extent does our understanding of the nervous system depend on the ways of knowing (such as reason, sense perception, and imagination)? (will be continued as entry ticket for next session)