Lecture Notes: Understanding Thoughts and Neural Communication

Introduction to Thoughts

• Origin of Thoughts: Initially explained simplistically as originating from the head.
• Actual Explanation: Thoughts come from the brain, specifically the neurons.
• Neurons: About 100 billion in the brain; responsible for communication which results in thoughts, feelings, emotions, and memories.

Neuronal Communication

• Synapse: Gap between neurons where communication occurs.
• Neurotransmitters: Chemicals that allow neurons to communicate across the synapse.

Importance of Neurotransmitters

• Role: Every thought, emotion, memory depends on neurotransmitters.
• Types: Estimated 30-100 types, with about 10 managing most brain functions.
• Key Neurotransmitters:
  • Acetylcholine (ACh): Involved in motor movement and memory. Linked to Alzheimer's when deficient.
  • Dopamine: Affects motor movement, alertness. Excess linked to schizophrenia; deficiency linked to Parkinson’s.
  • Serotonin: Regulates mood; deficiency linked to depression.
  • Endorphins: Manage pain; released during exercise, similar effect to opiates.
  • Norepinephrine: Involved in alertness and arousal; deficiency linked to depression.
  • GABA: Related to sleep issues.

Neural Anatomy

• Dendrites: Receive neurotransmitters from synapse.
• Soma (Cell Body): Processes messages.
• Axon: Transmits electrical messages; insulated by myelin sheath.
• Myelin Sheath: Fat layer insulating axon; breakdown causes multiple sclerosis.
• Terminal Buttons: Store and release neurotransmitters.

Neural Firing Process

• Resting Potential: Neuron at rest with a negative charge.
• Threshold: Level at which neuron fires.
• Action Potential: Process of firing, involving ion exchange causing an electrical charge.
• Reuptake: Process where unused neurotransmitters are reabsorbed.

Impact of Drugs

• Agonists: Mimic neurotransmitters causing neuron to fire.
• Antagonists: Block neuron firing.
• Reuptake Inhibitors: Prevent reuptake, increasing neurotransmitter levels in synapse.
  • Example: Cocaine is a dopamine reuptake inhibitor, leading to excess dopamine and the sensation of a 'high'.
  • Antidepressants: Often SSRIs, inhibit serotonin reuptake, aiming to alleviate depression.

Conclusion

• Summary: Overview of neural communication, neurotransmitters, and drug effects.
• Note: Information simplified for educational purposes.
• Personal Commentary: Reference to personal life and interests.