Autoradiographic comparison of [125I]LSD-labeled 5-HT2A receptor distribution in rat and guinea pig brain.
S W Watts, S L Gackenheimer, D R Gehlert, M L Cohen
Neurochemistry International June 1, 1994 DOI: 10.1016/0197-0186(94)90009-4 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | In vitro autoradiographic binding study Peer reviewed |
|---|---|
| Population | Brain sections from rats and guinea pigs |
| Topics | LSD Serotonin |
| Keywords | Animals Guinea pigs Rats, sprague-dawley Iodine radioisotopes Sulpiride Spiperone Receptors, serotonin Autoradiography Organ specificity Species specificity Binding, competitive Kinetics Male |
| Key points | The authors report that 5-HT2A receptor distribution and relative density are generally similar in rat and guinea pig brain, with highest binding in the claustrum and cortical Layer 4, but that species differences exist in the tenia tecta and mammillary nuclei, where rats show high binding and guinea pigs show little. |
Abstract
Although the density and distribution of 5-HT2A (5-hydroxytryptamine-2A) receptors is well established for rat brain, the 5-HT2A receptor distribution and density in guinea pig brain has not been extensively studied. In the present in vitro study, we have utilized 125I-lysergic acid diethylamide ([125I]LSD) to quantify and compare 5-HT2A receptor density in coronal sections of rat and guinea pig brain. Spiperone (1 microM) and sulpiride (1 microM) were used to displace [125I]LSD binding from 5-HT2A and D2 binding sites, respectively. Ligand binding was quantified by computer-aided image analysis densitometry (MCID). Similar to the rat, areas of highest specific 5-HT2A receptor binding (fmol/mg protein) in guinea pig brain included the claustrum and Layer 4 of the cerebral cortex. Significant binding was also found in remaining neocortical layers, islands of Calleja, caudate putamen, olfactory bulb, nucleus accumbens, and choroid plexus. While the rat brain exhibited a high level of specific binding in the tenia tecta and mammillary nuclei, little binding was observed in these regions in the guinea pig. In both rat and guinea pig, low specific binding was found in amygdaloid, thalamic, or cerebellar areas. These studies indicate a general similarity between 5-HT2A binding site distribution and relative density in guinea pig and rat brain but point to a few brain regions where significant differences exist.
Comparable studies
Other preclinical and animal studies on LSD, most cited first.
Citations in the library
Cited by 5
- Psychedelics in Psychiatry: Neuroplastic, Immunomodulatory, and Neurotransmitter Mechanisms Pharmacological Reviews December 16, 2020
- Structure–activity relationships of serotonin 5‐HT2Aagonists Wiley Interdisciplinary Reviews Membrane Transport and Signalling February 28, 2012
- Three Cases of Reported Improvement in Microsmia and Anosmia Following Naturalistic Use of Psilocybin and LSD Journal of Psychoactive Drugs August 31, 2023
- Therapeutic Potential of Psychedelics for Treating Anosmia: An Investigation of Online Accounts Journal of Psychoactive Drugs March 1, 2025
- Psychedelics and the thalamocortical system: A scoping review Pharmacology, Biochemistry, and Behavior July 9, 2026