Serotonergic Hyperactivity as a Potential Factor in Developmental, Acquired and Drug-Induced Synesthesia
Frontiers in Human Neuroscience 2013 DOI: 10.3389/fnhum.2013.00657 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Theoretical or philosophical paper Peer reviewed |
|---|---|
| Topics | Serotonin |
| Keywords | Synesthesia Perception |
| Citations | 46 |
| Key points | Argues that excessive serotonin levels may be a common mechanism across some cases of acquired, developmental, and drug-induced synesthesia. |
Abstract
Though synesthesia research has seen a huge growth in recent decades, and tremendous progress has been made in terms of understanding the mechanism and cause of synesthesia, we are still left mostly in the dark when it comes to the mechanistic commonalities (if any) among developmental, acquired and drug-induced synesthesia. We know that many forms of synesthesia involve aberrant structural or functional brain connectivity. Proposed mechanisms include direct projection and disinhibited feedback mechanisms, in which information from two otherwise structurally or functionally separate brain regions mix. We also know that synesthesia sometimes runs in families. However, it is unclear what causes its onset. Studies of psychedelic drugs, such as psilocybin, LSD and mescaline, reveal that exposure to these drugs can induce synesthesia. One neurotransmitter suspected to be central to the perceptual changes is serotonin. Excessive serotonin in the brain may cause many of the characteristics of psychedelic intoxication. Excessive serotonin levels may also play a role in synesthesia acquired after brain injury. In brain injury sudden cell death floods local brain regions with serotonin and glutamate. This neurotransmitter flooding could perhaps result in unusual feature binding. Finally, developmental synesthesia that occurs in individuals with autism may be a result of alterations in the serotonergic system, leading to a blockage of regular gating mechanisms. I conclude on these grounds that one commonality among at least some cases of acquired, developmental and drug-induced synesthesia may be the presence of excessive levels of serotonin, which increases the excitability and connectedness of sensory brain regions.
Comparable studies
Other theoretical and historical papers on serotonin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Psychedelics as Medicines: An Emerging New Paradigm General population | 2016 | Theoretical or philosophical paper | |
| Beyond the dopamine hypothesis of schizophrenia to three neural networks of psychosis: dopamine, serotonin, and glutamate | 2018 | Theoretical or philosophical paper | |
| A Dendrite-Focused Framework for Understanding the Actions of Ketamine and Psychedelics | 2020 | Theoretical or philosophical paper | |
| Dreams, Hallucinogenic Drug States, and Schizophrenia: A Psychological and Biological Comparison | 1983 | Theoretical or philosophical paper | |
| Understanding the effects of serotonin in the brain through its role in the gastrointestinal tract. | 2022 | Theoretical or philosophical paper |
Citations in the library
Cited by 16
- Phenomenology, Structure, and Dynamic of Psychedelic States Current Topics in Behavioral Neurosciences 2016
- Unifying Theories of Psychedelic Drug Effects Frontiers in Pharmacology March 2, 2018
- Unconscious Imagination and the Mental Imagery Debate Frontiers in Psychology May 23, 2017
- Relief from intractable phantom pain by combining psilocybin and mirror visual-feedback (MVF) Neurocase March 4, 2018
- A placebo-controlled investigation of synaesthesia-like experiences under LSD. Neuropsychologia April 5, 2016
and 11 more in the library
Cites 11
- Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin Proceedings of the National Academy of Sciences January 23, 2012
- Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action Neuroreport December 1, 1998
- Activation of Serotonin 2A Receptors Underlies the Psilocybin-Induced Effects on Oscillations, N170 Visual-Evoked Potentials, and Visual Hallucinations Journal of Neuroscience June 19, 2013
- Visual Phenomenology of the LSD Flashback Archives of General Psychiatry August 1, 1983
- Hallucinogen actions on human brain revealed Proceedings of the National Academy of Sciences January 30, 2012
and 6 more in the library