{"doi":"10.1177/0271678x251389042","title":"Cannabinoid 1 receptor occupancy and neurovascular responses induced by agonist, antagonist/inverse-agonist and potential modulator in non-human primate brains: PET/fMRI study","abstract":"The cannabinoid 1 receptor (CB1R) is a key pharmacological target in the central nervous system, modulating emotions, cognition, and memory. Functional interactions between CB1R and mu-opioid receptors (MOR) in analgesia have been reported. This study investigated CB1R occupancy and neuronal activation in non-human primate brains following acute administration of a CB1R agonist (CP55,940), an antagonist/inverse-agonist (rimonabant), an MOR agonist (morphine) using simultaneous positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). [ 11 C]OMAR, a CB1R-selective radiotracer, PET scans were acquired using bolus or bolus-plus-infusion protocols. Rimonabant (1, 3 mg/kg, n = 1 for each) reduced [ 11 C]OMAR non-displaceable binding potential by 25%–40% in CB1R-rich regions. To our knowledge, this is the first in vivo demonstration of CB1R occupancy by the agonist CP55,940 (0.05 mg/kg, n = 2), which displaced 15%–30% of [ 11 C]OMAR volume of distribution (V T ) in CB1R-rich regions. Although there was no clear dose–response relationship, CP55,940 increased cerebral blood volume (CBV), whereas rimonabant caused a biphasic response. Morphine administration (1 mg/kg, n = 2) reduced CBV in MOR-rich areas and modestly increased [ 11 C]OMAR V T , suggesting a potential indirect modulation of CB1R availability. Given the small sample size and variability close to test–retest levels, these preliminary findings should be interpreted with caution.","journal":"Journal of Cerebral Blood Flow & Metabolism","year":2025,"id":579921,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.961,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":426549,"name":"Yulong Xu","orcid":"0000-0001-9024-7311","position":1,"is_corresponding":false},{"id":915358,"name":"Frederick A. Bagdasarian","orcid":"0000-0001-5136-4494","position":2,"is_corresponding":false},{"id":1260172,"name":"Yu-Shiuan Lin","orcid":"0000-0002-3049-4166","position":3,"is_corresponding":false},{"id":329739,"name":"Changning Wang","orcid":"0000-0002-2076-4193","position":4,"is_corresponding":false},{"id":308504,"name":"Hsiao‐Ying Wey","orcid":"0000-0002-1425-8489","position":5,"is_corresponding":false},{"id":1138863,"name":"Chi‐Hyeon Yoo","orcid":"0000-0001-5234-4583","position":0,"is_corresponding":true}],"reference_count":77,"raw_metadata":null,"created_at":"2026-07-19T02:58:34.718602Z","pmid":"41185392","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}