Dopamine

• Dopamine helps transmit signals between nerve cells and is involved in how we feel pleasure. It’s often called the “feel-good” chemical, especially in the context of reward-driven behavior.

Synthesis of Dopamine:

• Step 1: Conversion to L-DOPA:

  • Enzyme: Tyrosine hydroxylase.
  • Process: Tyrosine is hydroxylated to form L-dihydroxyphenylalanine (L-DOPA).
  • Cofactors Required: Tetrahydrobiopterin (BH4) and oxygen.
  • Mechanism: BH4 acts as a cofactor, and oxygen adds a hydroxyl group to the benzene ring of tyrosine, forming L-DOPA.

• Step 2: Conversion to Dopamine:

  • Enzyme: Aromatic L-amino acid decarboxylase.
  • Process: L-DOPA is decarboxylated to form dopamine.
  • Cofactor Required: Pyridoxal phosphate (vitamin B6).
  • Mechanism: The enzyme removes a carboxyl group from L-DOPA, resulting in the formation of dopamine.

Significance of Dopamine:

1. Movement Regulation: It is crucial for the coordination of voluntary movements.
2. Motivation and Reward: It plays a key role in the brain’s reward system, influencing motivation, pleasure, and reinforcement learning.
3. Basal Ganglia Function: It is essential for the proper functioning of the basal ganglia, a brain region involved in movement control.

Clinical Relevance:

1. Parkinson’s Disease: Characterized by low levels in the brain, leading to movement disorders.
2. Schizophrenia: Linked to dysregulation of pathways.
3. Addiction: It pathways are involved in the mechanisms of addiction and reinforcement of addictive behaviors.

Thank you for reading from Firsthope's notes, don't forget to check YouTube videos!