Lysergic acid diethylamide (LSD) reduces associative brain connectivity while increasing sensory-somatomotor and thalamic connectivity. These neural effects, along with the subjective experience, are fully blocked by ketanserin, a selective 5-HT2A receptor antagonist. The spatial pattern of LSD's effects across the brain matches the distribution of 5-HT2A receptor gene expression in humans. These results strongly implicate the 5-HT2A receptor in LSD's neuropharmacology, informing the neurobiology of psychedelics and guiding development of psychedelic-based therapeutics.
Psilocybin, a hallucinogen derived from mushrooms, significantly enhances serotonin receptor activity, leading to notable changes in brain connectivity. In a study with 30 participants, functional magnetic resonance imaging revealed a 60% increase in functional connectivity in areas linked to sensory processing and emotional regulation after psilocybin administration. This shift suggests profound implications for psychology and medicine, particularly in treating mental health disorders. The findings underscore the potential of psychedelics in pharmacology, highlighting their ability to influence behavior through neurotransmitter pathways and chemical synthesis of alkaloids.
Ketamine is a promising therapy for treatment-resistant depression, but why some people respond better than others remains unclear. The molecular mechanisms of ketamine are not yet connected to its effects on brain activity and behavior.