Dose-dependent changes in global brain activity and functional connectivity following exposure to psilocybin: a BOLD MRI study in awake rats

Psilocybin is a hallucinogen with complex neurobiological and behavioral effects. This is the first study to use MRI to follow functional changes in brain activity in response to different doses of psilocybin in fully awake, drug naive rats. We hypothesized that psilocybin would show a dose-dependen...

Full description

Saved in:
Bibliographic Details
Main Authors: Evan Fuini, Arnold Chang, Richard J. Ortiz, Taufiq Nasseef, Josh Edwards, Marc Latta, Elias Gonzalez, Taylor J. Woodward, Bryce Axe, Ashwath Maheswari, Noah Cavallaro, Heather B. Bradshaw, Praveen P. Kulkarni, Craig F. Ferris
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-05-01
Series:Frontiers in Neuroscience
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fnins.2025.1554049/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849713229251477504
author Evan Fuini
Arnold Chang
Richard J. Ortiz
Richard J. Ortiz
Taufiq Nasseef
Josh Edwards
Marc Latta
Elias Gonzalez
Taylor J. Woodward
Bryce Axe
Ashwath Maheswari
Noah Cavallaro
Heather B. Bradshaw
Praveen P. Kulkarni
Craig F. Ferris
Craig F. Ferris
author_facet Evan Fuini
Arnold Chang
Richard J. Ortiz
Richard J. Ortiz
Taufiq Nasseef
Josh Edwards
Marc Latta
Elias Gonzalez
Taylor J. Woodward
Bryce Axe
Ashwath Maheswari
Noah Cavallaro
Heather B. Bradshaw
Praveen P. Kulkarni
Craig F. Ferris
Craig F. Ferris
author_sort Evan Fuini
collection DOAJ
description Psilocybin is a hallucinogen with complex neurobiological and behavioral effects. This is the first study to use MRI to follow functional changes in brain activity in response to different doses of psilocybin in fully awake, drug naive rats. We hypothesized that psilocybin would show a dose-dependent increase in activity in the prefrontal cortex and thalamus, while decreasing hippocampal activity. Female and male rats were given IP injections of vehicle or psilocybin in doses of 0.03 mg/kg, 0.3 mg/kg, and 3.0 mg/kg while fully awake during the imaging session. These levels were validated by measuring psilocybin and its metabolite, psilocin. Changes in BOLD signal were recorded over a 20 min window. Data for resting state functional connectivity were collected approximately 35 min post injection. All data were registered to rat 3D MRI atlas with 169 brain areas providing site-specific changes in global brain activity and changes in functional connectivity. Treatment with psilocybin resulted in a significant dose-dependent increase in positive BOLD signal. The areas most affected by the acute presentation of psilocybin were the somatosensory cortex, basal ganglia and thalamus. Males and females showed different sensitivity to psilocybin dose, with females exhibiting greater activation than males at 0.3 mg/kg, especially in thalamic and basal ganglia regions. There was a significant dose-dependent global increase in functional connectivity, highlighted by hyperconnectivity to the cerebellum. Brain areas hypothesized to be involved in loss of sensory filtering and organization of sensory motor stimuli, such as the cortico-striato-thalamo-cortical circuit and the claustrum, showed increased activation at higher doses of psilocybin. Indeed, the general neuroanatomical circuitry associated with the psychedelic experience was affected but the direction of the BOLD signal and pattern of activity between neural networks was inconsistent with the human literature.
format Article
id doaj-art-74fd6c3596bb4df88e6a3c867bd803e1
institution DOAJ
issn 1662-453X
language English
publishDate 2025-05-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Neuroscience
spelling doaj-art-74fd6c3596bb4df88e6a3c867bd803e12025-08-20T03:14:01ZengFrontiers Media S.A.Frontiers in Neuroscience1662-453X2025-05-011910.3389/fnins.2025.15540491554049Dose-dependent changes in global brain activity and functional connectivity following exposure to psilocybin: a BOLD MRI study in awake ratsEvan Fuini0Arnold Chang1Richard J. Ortiz2Richard J. Ortiz3Taufiq Nasseef4Josh Edwards5Marc Latta6Elias Gonzalez7Taylor J. Woodward8Bryce Axe9Ashwath Maheswari10Noah Cavallaro11Heather B. Bradshaw12Praveen P. Kulkarni13Craig F. Ferris14Craig F. Ferris15Department Pharmaceutical Sciences, Northeastern University, Boston, MA, United StatesCenter for Translational Neuroimaging, Northeastern University, Boston, MA, United StatesDepartment of Chemistry & Biochemistry, New Mexico State University, Las Cruces, NM, United StatesDepartment of Psychology, Northern Illinois University, DeKalb, IL, United StatesDepartment of Mathematics, College of Science & Humanity Studies, Riyadh, Saudi ArabiaDepartment Pharmaceutical Sciences, Northeastern University, Boston, MA, United StatesDepartment Pharmaceutical Sciences, Northeastern University, Boston, MA, United StatesDepartment Pharmaceutical Sciences, Northeastern University, Boston, MA, United StatesPsychological & Brain Sciences, Program in Neuroscience, Indiana University, Bloomington, IN, United StatesDepartment Pharmaceutical Sciences, Northeastern University, Boston, MA, United StatesDepartment Pharmaceutical Sciences, Northeastern University, Boston, MA, United StatesDepartment Pharmaceutical Sciences, Northeastern University, Boston, MA, United StatesPsychological & Brain Sciences, Program in Neuroscience, Indiana University, Bloomington, IN, United StatesCenter for Translational Neuroimaging, Northeastern University, Boston, MA, United StatesCenter for Translational Neuroimaging, Northeastern University, Boston, MA, United StatesDepartment Psychology & Pharmaceutical Sciences, Northeastern University, Boston, MA, United StatesPsilocybin is a hallucinogen with complex neurobiological and behavioral effects. This is the first study to use MRI to follow functional changes in brain activity in response to different doses of psilocybin in fully awake, drug naive rats. We hypothesized that psilocybin would show a dose-dependent increase in activity in the prefrontal cortex and thalamus, while decreasing hippocampal activity. Female and male rats were given IP injections of vehicle or psilocybin in doses of 0.03 mg/kg, 0.3 mg/kg, and 3.0 mg/kg while fully awake during the imaging session. These levels were validated by measuring psilocybin and its metabolite, psilocin. Changes in BOLD signal were recorded over a 20 min window. Data for resting state functional connectivity were collected approximately 35 min post injection. All data were registered to rat 3D MRI atlas with 169 brain areas providing site-specific changes in global brain activity and changes in functional connectivity. Treatment with psilocybin resulted in a significant dose-dependent increase in positive BOLD signal. The areas most affected by the acute presentation of psilocybin were the somatosensory cortex, basal ganglia and thalamus. Males and females showed different sensitivity to psilocybin dose, with females exhibiting greater activation than males at 0.3 mg/kg, especially in thalamic and basal ganglia regions. There was a significant dose-dependent global increase in functional connectivity, highlighted by hyperconnectivity to the cerebellum. Brain areas hypothesized to be involved in loss of sensory filtering and organization of sensory motor stimuli, such as the cortico-striato-thalamo-cortical circuit and the claustrum, showed increased activation at higher doses of psilocybin. Indeed, the general neuroanatomical circuitry associated with the psychedelic experience was affected but the direction of the BOLD signal and pattern of activity between neural networks was inconsistent with the human literature.https://www.frontiersin.org/articles/10.3389/fnins.2025.1554049/fullpsilocincerebellar nucleiBOLD resting state functional connectivity5-HT2A receptorhyperconnectivity
spellingShingle Evan Fuini
Arnold Chang
Richard J. Ortiz
Richard J. Ortiz
Taufiq Nasseef
Josh Edwards
Marc Latta
Elias Gonzalez
Taylor J. Woodward
Bryce Axe
Ashwath Maheswari
Noah Cavallaro
Heather B. Bradshaw
Praveen P. Kulkarni
Craig F. Ferris
Craig F. Ferris
Dose-dependent changes in global brain activity and functional connectivity following exposure to psilocybin: a BOLD MRI study in awake rats
Frontiers in Neuroscience
psilocin
cerebellar nuclei
BOLD resting state functional connectivity
5-HT2A receptor
hyperconnectivity
title Dose-dependent changes in global brain activity and functional connectivity following exposure to psilocybin: a BOLD MRI study in awake rats
title_full Dose-dependent changes in global brain activity and functional connectivity following exposure to psilocybin: a BOLD MRI study in awake rats
title_fullStr Dose-dependent changes in global brain activity and functional connectivity following exposure to psilocybin: a BOLD MRI study in awake rats
title_full_unstemmed Dose-dependent changes in global brain activity and functional connectivity following exposure to psilocybin: a BOLD MRI study in awake rats
title_short Dose-dependent changes in global brain activity and functional connectivity following exposure to psilocybin: a BOLD MRI study in awake rats
title_sort dose dependent changes in global brain activity and functional connectivity following exposure to psilocybin a bold mri study in awake rats
topic psilocin
cerebellar nuclei
BOLD resting state functional connectivity
5-HT2A receptor
hyperconnectivity
url https://www.frontiersin.org/articles/10.3389/fnins.2025.1554049/full
work_keys_str_mv AT evanfuini dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT arnoldchang dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT richardjortiz dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT richardjortiz dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT taufiqnasseef dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT joshedwards dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT marclatta dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT eliasgonzalez dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT taylorjwoodward dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT bryceaxe dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT ashwathmaheswari dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT noahcavallaro dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT heatherbbradshaw dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT praveenpkulkarni dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT craigfferris dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats
AT craigfferris dosedependentchangesinglobalbrainactivityandfunctionalconnectivityfollowingexposuretopsilocybinaboldmristudyinawakerats