Adjunct Faculty
Adjunct faculty typically have an academic or research appointment at another institution and contribute or collaborate with one or more School of Medicine faculty members or programs.
Adjunct rank detailsAnsel Hillmer, PhD
Associate Professor AdjunctDownloadHi-Res Photo
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Titles
Associate Professor Adjunct
Associate Director of Imaging, Positron Emission Tomography (PET)
Biography
Ansel obtained his Ph.D. in Medical Physics from the University of Wisconsin, Madison in 2014. His research program features core areas of translational characterization of novel PET radiotracers, developing new imaging paradigms to improve quantification of brain neurobiology, and human neuroimaging research studying mechanisms underlying diverse psychiatric conditions. Research efforts are complemented by didactic activities lecturing at Yale and individual mentoring of trainees. Current projects include characterizing novel PET radiotracers of immune-related targets in the brain; developing novel imaging paradigms to study acute alcohol effects on neuroimmune and glutamate systems; assessment of dopamine release from smoked cannabis; method development for analyzing multimodal imaging data from fMRI-PET or PET-PET datasets; and implementing Independent Component Analysis (ICA) to identify different sources of PET radiotracer uptake.
Last Updated on April 07, 2025.
Appointments
Psychiatry
Associate Professor AdjunctPrimary
Other Departments & Organizations
Education & Training
- Post-Doctoral Fellow
- Yale University (2016)
- PhD
- University of Wisconsin, Medical Physics (2014)
- MS
- University of Wisconsin, Medical Physics (2011)
- BS
- Valparaiso University, Physics (2009)
Research
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Overview
Medical Research Interests
Alcohol-Related Disorders; Analytical, Diagnostic and Therapeutic Techniques and Equipment; Neuroimaging; Stress Disorders, Post-Traumatic; Substance Withdrawal Syndrome
ORCID
0000-0002-8105-1381
Research at a Glance
Yale Co-Authors
Frequent collaborators of Ansel Hillmer's published research.
Publications Timeline
A big-picture view of Ansel Hillmer's research output by year.
Research Interests
Research topics Ansel Hillmer is interested in exploring.
Richard Carson, PhD
Kelly Cosgrove, PhD
David Matuskey, MD
Nabeel Nabulsi, PhD
Yiyun Huang, PhD
Irina Esterlis, PhD
36Publications
389Citations
Stress Disorders, Post-Traumatic
Neuroimaging
Publications
2025
Imaging Metabotropic Glutamate Receptor 5 and Excitatory Neural Activity in Autism.
Naples A, Yang Y, Gravel P, Toyonaga T, Sadabad F, Koohsari S, Pittman B, Gallezot J, Pisani L, Finn C, Cramer-Benjamin S, Herman N, Rosenthal L, Franke C, Walicki B, Rodden I, Hillmer A, Esterlis I, Ropchan J, Nabulsi N, Huang Y, Wolf J, Carson R, McPartland J, Matuskey D. Imaging Metabotropic Glutamate Receptor 5 and Excitatory Neural Activity in Autism. American Journal Of Psychiatry 2025, appiajp20241084. PMID: 41366835, DOI: 10.1176/appi.ajp.20241084.Peer-Reviewed Original ResearchCitationsAltmetricConceptsMetabotropic glutamate receptor 5Glutamate receptor 5Positron emission tomographyAutistic groupGroup differencesPositron emission tomography outcomes measurementsExcitatory neurotransmissionNeurotypical control participantsAutism spectrum disorderReceptor 5Receptor availabilityAutism phenotypeAutistic adultsBrain areasBrain regionsExcitatory neural activitySpectrum disorderControl participantsSensory sensitivityMGlu5Neural activityVenous input functionsReceptor densityAutismEEG power spectraImaging Neuroimmune Dysfunction: From TSPO to Emerging PET Targets
Bonomi R, Raval N, Hillmer A, Cosgrove K. Imaging Neuroimmune Dysfunction: From TSPO to Emerging PET Targets. Biological Psychiatry 2025 PMID: 41297785, DOI: 10.1016/j.biopsych.2025.11.010.Peer-Reviewed Original ResearchAltmetricConceptsPositron emission tomographyPET targetsBrain-resident immune cellsPET imaging biomarkersResident immune cellsDevelopment of novel radiotracersTranslocator proteinPositron emission tomography imagingPsychiatric disordersPsychiatric illnessNeuroimmune systemImmune cellsDiagnostic strategiesNovel radiotracersImaging biomarkersEmission tomographyMicroglial levelsTherapeutic targetIn vivoNeuroimmuneExceptional brain PET images from the NeuroEXPLORER: scans with targeted radiopharmaceuticals and comparison to HRRT
Volpi T, Toyonaga T, Khattar N, Gallezot J, Naganawa M, Vanderlinden G, Honhar P, Zeng T, Fontaine K, Mulnix T, Hu L, Sun X, Henry S, Matuskey D, Radhakrishnan R, Guo L, Hu Y, Zhang J, Zheng X, Nabulsi N, Huang Y, Badawi R, Cherry S, Hillmer A, Jones T, Liu C, Morris E, Qi J, Li H, Carson R. Exceptional brain PET images from the NeuroEXPLORER: scans with targeted radiopharmaceuticals and comparison to HRRT. European Journal Of Nuclear Medicine And Molecular Imaging 2025, 1-12. PMID: 41177836, DOI: 10.1007/s00259-025-07605-4.Peer-Reviewed Original ResearchCitationsAltmetricConceptsStandardized uptake valueTargeted radiopharmaceuticalsDopamine systemMultiple cortical areasSerotonin transporterRaphe nucleusMeasurement of tracer uptakeBrain regionsBrain structuresSubcortical nucleiPositron emission tomographyCortical areasSynaptic densityPET researchFocal uptakePaired scansUptake valueTracer uptakePET systemGray matterEarly imagesEmission tomographyHealthy individualsTracer deliveryNeuroExplorerCarotid Artery Image-Derived Blood Time-Activity Curves on the NeuroEXPLORER: Initial Multitracer Validation Against Arterial Sampling.
Volpi T, Gallezot J, Henry S, Dias M, Khattar N, Toyonaga T, Fontaine K, Mulnix T, Zhang J, Guo L, Gravel P, Radhakrishnan R, Hillmer A, Matuskey D, Carson R. Carotid Artery Image-Derived Blood Time-Activity Curves on the NeuroEXPLORER: Initial Multitracer Validation Against Arterial Sampling. Journal Of Nuclear Medicine 2025, 66: 1993-2001. PMID: 41043999, PMCID: PMC12676648, DOI: 10.2967/jnumed.125.270414.Peer-Reviewed Original ResearchCitationsAltmetricMeSH Keywords and ConceptsConceptsArea under the curveCommon carotidTime-activity curvesLate area under the curveMethods:Carotid arteryRegions-of-interestResults:Blood samplesPartial volume effectsImage-derived input functionArterial blood samplesArterial input functionAlternative to arterial blood samplingBlood time-activity curvesPET kinetic modelingGold standardInput functionBackground activityArterial samplesCarotidBrain-dedicated PET scannersBrain PETCannabinoid 1 receptor availability in posttraumatic stress disorder: A positron emission tomography study
Korem N, Bassir Nia A, Hillmer A, D’Souza D, Nabulsi N, Ropchan J, Huang Y, Cosgrove K, Levy I, Pietrzak R, Harpaz-Rotem I. Cannabinoid 1 receptor availability in posttraumatic stress disorder: A positron emission tomography study. Translational Psychiatry 2025, 15: 310. PMID: 40846835, PMCID: PMC12373994, DOI: 10.1038/s41398-025-03519-9.BooksCitationsAltmetricConceptsPathophysiology of posttraumatic stress disorderEmotional numbing symptomsCB1R availabilityPosttraumatic stress disorderEndocannabinoid systemStress disorderPositron emission tomographyTrauma-exposed participantsEndocannabinoid system's rolePositron emission tomography studiesCannabinoid receptor 1Emission tomography studiesMulti-faceted disorderFear learningCB1RSymptom expressionHealthy controlsCannabinoidDisordersTomography studiesEmission tomographyPreclinical studiesSymptomsHigher levelsReceptor 1Greater Neuroimmune System Deficit in Women Than Men With Alcohol Use Disorder
Zakiniaeiz Y, Hillmer A, Shi H, Pittman B, Nabulsi N, Huang Y, Bonomi R, Matuskey D, Angarita G, McKee S, Cosgrove K. Greater Neuroimmune System Deficit in Women Than Men With Alcohol Use Disorder. Biological Psychiatry 2025, 99: 49-56. PMID: 40412787, PMCID: PMC12353993, DOI: 10.1016/j.biopsych.2025.05.012.Peer-Reviewed Original ResearchCitationsAltmetricConceptsTranslocator protein availabilityAlcohol-induced neurodegenerationExecutive function tasksConsequences of alcohol useAlcohol use disorderBrain imaging scansTranslocator protein levelsSex-matched controlsExecutive functionLower hippocampalTSPO availabilityFrontal cortexTranslocator proteinUse disorderNeurocognitive functionBrain regionsSex differencesAlcohol useBrain-resident immune cellsNeuroimmune mechanismsFunctional tasksSystem deficitsAUDImaging scansNeuroimmune cells611. Cannabinoid 1 Receptor Availability in Men With Opioid Use Disorder: A Positron Emission Tomography Study
Nia A, Hillmer A, Aghaei A, Pittman B, Huang H, Nabulsi N, D'Souza D. 611. Cannabinoid 1 Receptor Availability in Men With Opioid Use Disorder: A Positron Emission Tomography Study. Biological Psychiatry 2025, 97: s350. DOI: 10.1016/j.biopsych.2025.02.850.Peer-Reviewed Original ResearchAcute Alcohol‐Induced Changes Measured With Metabotropic Glutamate Receptor 5 Positron Emission Tomography
Raval N, Smart K, Angarita G, Miller R, Huang Y, Krystal J, Carson R, Cosgrove K, O'Malley S, Hillmer A. Acute Alcohol‐Induced Changes Measured With Metabotropic Glutamate Receptor 5 Positron Emission Tomography. Addiction Biology 2025, 30: e70031. PMID: 40309934, PMCID: PMC12044519, DOI: 10.1111/adb.70031.Peer-Reviewed Original ResearchMeSH Keywords and ConceptsConceptsBlood alcohol levelsAlcohol challengeEffects of acute alcohol consumptionPeak blood alcohol levelsLaboratory alcohol challengeNon-displaceable binding potentialMetabotropic glutamate receptor 5Acute alcohol challengeGlutamate releaseAlcohol-induced changesGlutamate receptor 5Alcohol consumptionAcute alcohol consumptionMGluR5 availabilityPET scansSocial drinkersEthanol doseAlcohol effectsBrain regionsAcute alcoholBinding potentialCortical regionsClinically relevant dosesDrinking occasionsAlcohol levels452. Examining the Role of the Kappa Opioid Receptor in Trauma-Related Psychopathology and Chronic Pain Using [11C]EKAP Positron Emission Tomography
Weiss E, Hart-Derrick V, Freeman D, Miller R, Hillmer A, Wagner A, Matuskey D, Esterlis I, Davis M. 452. Examining the Role of the Kappa Opioid Receptor in Trauma-Related Psychopathology and Chronic Pain Using [11C]EKAP Positron Emission Tomography. Biological Psychiatry 2025, 97: s283. DOI: 10.1016/j.biopsych.2025.02.690.Peer-Reviewed Original ResearchCorrecting SUVR bias by accounting for radiotracer clearance in tissue: A validation study with [18F]FE-PE2I PET in cross-sectional, test-retest and longitudinal cohorts
Oh M, Honhar P, Carson R, Hillmer A, Varrone A. Correcting SUVR bias by accounting for radiotracer clearance in tissue: A validation study with [18F]FE-PE2I PET in cross-sectional, test-retest and longitudinal cohorts. Journal Of Cerebral Blood Flow And Metabolism : Official Journal Of The International Society Of Cerebral Blood Flow And Metabolism 2025, 45: 1357-1370. PMID: 39981611, PMCID: PMC11846093, DOI: 10.1177/0271678x251322407.Peer-Reviewed Original Research
News
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News
- August 23, 2024
Microglia-Mediated Neuroimmune Suppression in PTSD Is Associated With Anhedonia
- September 22, 2022
Hillmer Awarded Grant to Develop Brain Imaging Tool to Study the Brain’s Immune System
- September 15, 2022
Bassir Nia Receives National Institute on Drug Abuse Grant
- September 13, 2022
Inaugural Yale Conference on Alcohol Research and Education (YCARE) Convenes Diverse Audience for an Interdisciplinary Day of Learning
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