Lecture Notes: The Brain's Reward Circuit

Introduction to the Limbic System

• Deep structure within the brain.
• Contains the brain's reward circuit.

Reward Circuit

• Links brain structures controlling/regulating pleasure.
• Motivation through the sensation of pleasure.

Activation Process

• Involves electrical and chemical signal relays.
• Synapse: Gap between sending and receiving cells.

Role of Dopamine

• Dopamine Neurons: Release neurotransmitter dopamine.
• Dopamine crosses synapse to engage with dopamine receptors.
• Dopamine Receptors: Proteins on receiving cell surfaces.
• Signal transmission inside cell when dopamine binds externally.

Dopamine Recycling

• Some dopamine returns to sending cell via transporters.
• Re-released dopamine contributes to signaling efficiency.

Response to Rewards

• Pre-synaptic cell releases more dopamine when rewards are present.
• Dopamine transporters remove excess quickly.

Learning and Adaptation

• Dopamine surges help brain learn and adapt.

Impact of Drugs

• Drugs can hijack the reward process.
• Leads to unhealthy behaviors and consequences.

These notes capture the essential details of the brain's reward circuit as discussed in the lecture, focusing on the role of dopamine in pleasure and behavioral motivation.