BIOL 412: Course Structure and Neurobiology of Learning - Long-Term Potentiation

BIOL 412 Learning Cycle and Neurobiology of Learning

BIOL 412 Learning Cycle: Facilitating Long-Term Potentiation (LTP)

The course structure for BIOL 412 is designed to facilitate robust learning and connection strengthening (analogous to LTP) through a cyclical process:

  1. READ: Utilize the provided Chapter Reading & Study Guide to focus your reading on specific sections.
    • Week 1 Readings:
      • Syllabus.
      • Chapter 35.1 in OpenStax Biology 2e: Introduction and "Parts of a Neuron" only (stop at "Types of Neurons").
      • Chapter 35.2 in OpenStax Biology 2e: Introduction, "Neuronal Charged Membranes," "Resting Membrane Potential," "Chemical Synapse," and "Synaptic Plasticity" sections only.
      • Chapter 1.1 in OpenStax Biology 2e.
  2. READING QUESTIONS: These are designed for mastering basic concepts and vocabulary.
    • Due: 12:10 pm on the first day of class for the week.
    • Attempts: You may complete it as many times as desired; the highest grade will be kept.
  3. ATTEND CLASS: This is where concepts are presented and practiced.
    • Activities: Lecture, Clicker Questions, Discussion, Model Construction, Group Work Activities.
    • Personal Practice: Take handwritten notes, practice problem-solving, and summarize notes, specifically focusing on the Learning Objectives.
    • Engagement: Dedicate time to thinking and learning, avoiding superficial answers.
  4. REVIEW: Strengthen your understanding through additional practice.
    • Activities: Complete Homework and answer practice questions.

Class Time: Group Work Importance and Logistics

Why Group Work?

Group work is a highly important component, as indicated by student surveys on skills gained:

  • Ability to work effectively in teams: 62\% very important, 31\% important.
  • Critical thinking skills: 60\% very important, 35\% important, 5\% not very important.
  • Ability to analyze and interpret data: 57\% very important, 34\% important.
  • Digital literacy: 56\% very important, 36\% important, 8\% not very important.
  • Ability to demonstrate complex problem-solving skills: 55\% very important, 36\% important, 9\% not very important.

Group Work Logistics:

  • Seating: On Fridays (starting in Week 2), you will sit with your designated group in a specific area.
  • Sign-ups: If you wish to join friends, follow Canvas directions and sign up before Friday at 5 pm, providing first and last names.
  • Random Placement: If you do not sign up, you will be randomly placed in a group.
  • Finalization: Groups will be finalized before September 5th.

Clicker Questions and In-Class Work:

  • Grading: Graded for completion during lecture and for accuracy during group work.
  • Absences: Missed in-class work cannot be made up.
  • Dropped Scores: 6 in-class scores will be dropped (equivalent to 6 excused absences).
  • Resources: PowerPoints are posted on myCourses before class. Lectures are not recorded.
  • Academic Buddy: It is highly recommended to have an academic buddy to obtain missed notes.

Neurobiology of Learning: Learning Objectives

  • Explain the principle "neurons that fire together, wire together" (Long-Term Potentiation) and its implications for memory formation.
  • Connect the overall structure of the BIOL 412 course to fundamental neurobiology concepts.
  • Explain the logistical details and expectations for BIOL 412.

Peer-Led Team Learning (PLTL)

Overview: PLTL is an OPTIONAL but HIGHLY RECOMMENDED weekly, student-led problem-solving session.

  • Commitment: Students need to commit to attending PLTL almost every week throughout the semester, starting in Week 3.
  • Grading Impact: PLTL attendance counts for 8\% of your grade, while Homework makes up 2\% of your grade.
  • Sign-ups: Announcements will be made for sign-ups, which are on a first-come, first-serve basis.

Why Participate in PLTL?

  • Deeper Learning: Enables you to learn the course material more deeply.
  • Accountability: Provides weekly accountability for practicing biology concepts, discouraging last-minute cramming.
  • Community: Connects you with other students in smaller group settings.
  • Mentorship: Offers access to peer mentors for guidance.

Form and Function of a Neuron: Notebook Exercise

  1. Draw and Label: Sketch two neurons, including a pre-synaptic neuron and a post-synaptic neuron. Label the following structures: synapse, dendrite, axon, neurotransmitters, and receptors.
  2. Describe Function: Answer these questions in your notebook:
    • Why is neuronal signaling referred to as electro-chemical signaling?
    • How is information transferred between cells? (Hint: Neurotransmitters open channels for ions).

Synaptic Plasticity Leads to Memory Formation and Learning

Long-Term Potentiation (LTP): Strengthening Neural Connections

  • Definition: LTP is the strengthening of neuronal connections through frequent use.
  • Core Principle: "Neurons that fire together, wire together."

One Mechanism for LTP in Memory Formation and Learning

This process involves the coordinated action of specific neurotransmitters and receptors:

  1. Glutamate Release: A pre-synaptic neuron fires, releasing the neurotransmitter Glutamate into the synaptic cleft.
  2. AMPA Receptor Activation: Glutamate binds to AMPA receptors on the post-synaptic neuron, causing them to open. This allows Na^+ ions to flow into the post-synaptic neuron, leading to a depolarization (weak connection).
  3. NMDA Receptor Blockade: Initially, NMDA receptors on the post-synaptic neuron are blocked by a Mg^{2+} ion.
  4. Depolarization and Mg$^{2+}$ Removal: When the pre-synaptic neuron fires repeatedly and strongly, it causes significant depolarization of the post-synaptic membrane via the AMPA receptors. This depolarization repels and unblocks the Mg^{2+} ion from the NMDA receptor.
  5. NMDA Receptor Activation: With the Mg^{2+} block removed, the NMDA receptor opens, allowing both Na^+ and, crucially, Ca^{2+} ions to flow into the post-synaptic neuron.
  6. Ca^{2+} Influx and Signaling Cascade: The influx of Ca^{2+} serves as a critical secondary messenger, initiating a cascade of intracellular events.
  7. AMPA Receptor Insertion: This cascade leads to the insertion of more AMPA receptors into the post-synaptic membrane.
  8. Strengthened Connection (LTP): The presence of more AMPA receptors means the post-synaptic neuron becomes more sensitive and more likely to signal in response to future glutamate release (strong connection). This persistent strengthening is LTP.

LTP: An Analogy

Think of LTP like building muscle strength through repeated workouts. After just one arm workout, your arms are still relatively weak (a weak neural connection). However, with consistent, frequent workouts, your arms become much stronger (a strong neural connection).

Building a Model of Long-Term Potentiation (LTP)

Models generally consist of:

  • Structures: The parts, elements, or components of a system (nouns).
  • Relationships: The processes or mechanisms operating within the system (verbs).
  • Functions: The role or purpose of the model.

SRF Model Instructions:

  1. Narrative Design: Design your model to "tell a story," illustrating its function.
  2. Structure Representation: Represent structures within boxes.
  3. Directional Arrows: Connect boxes with one or more directional arrows.
  4. Labeled Relationships: Label each arrow with specific relationships.

SRF Model of LTP Exercise:

Draw a model to illustrate how a neural connection is reinforced during long-term potentiation. Connect as many words as you can from the concept. At a minimum, include these structures:

  • Presynaptic neuron
  • Glutamate
  • AMPA receptor
  • Postsynaptic neuron
  • NMDA receptor
  • Ca^{2+} (Calcium ions)
  • Na^+ (Sodium ions)

You may add additional structures if desired. Remember to label your arrows with the relationship they represent.

Memory Storage and Recall: A Recap

  • Reinforcement: Repeated use of a specific neural pathway leads to an increase in AMPA receptors within those neurons. This makes the neurons more likely to signal when glutamate is present.
  • Recall: These strengthened neural connections represent memories that can be recalled.
  • Learning Variability: It's important to note that not all facts or skills are learned with the same ease or speed; learning efficiency can vary.