Lecture 3–The 5-HT2A Receptors and Brain Networks | Dr. Ali Garatli

This lesson focuses on the 5-HT2A receptor and its role in cortical activity, neuroplasticity, cognition, and emotional processing. It compares 5-HT2A with 5-HT1A, highlighting the difference between excitatory and inhibitory serotonin effects in the brain. The lesson also explores receptor distribution in cortical and limbic regions, the relationship between serotonin signaling and cognitive flexibility, and how these pathways may influence rumination, attention, mood states, and reward circuits. Clinical links are introduced through discussion of psychedelics, depression models, glutamate activity, and interactions between serotonin and dopamine pathways. Overall, the lesson connects receptor pharmacology with large-scale brain networks and relevant psychiatric symptoms.

Key topics:

• Functional differences between 5-HT2A and 5-HT1A receptors
• 5-HT2A as an excitatory receptor in cortical regions
• Role of 5-HT2A in neuroplasticity and cognitive flexibility
• Distribution of 5-HT2A receptors in cortex, limbic system, and related brain areas
• Relationship between serotonin pathways, dopamine release, and reward circuits
• Brain network models involving rumination, attention, and task-positive/default-mode states
• Clinical relevance to depression, psychedelics, mania, and glutamatergic dysregulation