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
Yiyun Huang, PhD
Nabeel Nabulsi, PhD
Irina Esterlis, PhD
37Publications
492Citations
Stress Disorders, Post-Traumatic
Neuroimaging
Publications
2026
Neuroimaging evidence for a dopamine-independent association between motor cortex microstructure and Parkinson’s disease severity
Honhar P, Tinaz S, Ebrahimian Sadabad F, Dias M, Yang Y, Henry S, Hillmer A, Zakiniaeiz Y, Radhakrishnan R, Comley R, Zhang X, Hooker B, Zhang Y, Finnema S, Carson R, Scheinost D, Matuskey D. Neuroimaging evidence for a dopamine-independent association between motor cortex microstructure and Parkinson’s disease severity. Npj Parkinson's Disease 2026 PMID: 42248873, DOI: 10.1038/s41531-026-01411-x.Peer-Reviewed Original ResearchMultiple sources of β2*-nicotinic acetylcholine receptor binding are differentially affected during tobacco smoking abstinence as revealed by Independent Component Analysis of [18F]Flubatine PET images
Raval N, Calakos K, Zheng M, Huttner A, Esterlis I, Huang H, Calhoun V, Picciotto M, Cosgrove K, Hillmer A. Multiple sources of β2*-nicotinic acetylcholine receptor binding are differentially affected during tobacco smoking abstinence as revealed by Independent Component Analysis of [18F]Flubatine PET images. Neuropsychopharmacology 2026, 51: 1207-1216. PMID: 41559453, PMCID: PMC13213061, DOI: 10.1038/s41386-025-02311-z.Peer-Reviewed Original ResearchThis study investigates how smoking affects brain nicotinic acetylcholine receptor subtypes, showing distinct changes that could guide treatments for smoking cessation.“Pseudo-reference-based Input Function Shape” (pRef-IFS): Towards a True image-derived input function for PET kinetic modeling
Volpi T, Naganawa M, Carson R, Hillmer A. “Pseudo-reference-based Input Function Shape” (pRef-IFS): Towards a True image-derived input function for PET kinetic modeling. Journal Of Cerebral Blood Flow And Metabolism : Official Journal Of The International Society Of Cerebral Blood Flow And Metabolism 2026, 46: 1238-1252. PMID: 41543053, PMCID: PMC12811094, DOI: 10.1177/0271678x251411712.Peer-Reviewed Original ResearchCitationsAltmetricHigher drinking frequency corresponds to lower synaptic density in people with alcohol use disorder
Zakiniaeiz Y, Raval N, Riordan W, Nabulsi N, Huang Y, Pittman B, Matuskey D, Angarita G, Bonomi R, McKee S, Hillmer A, Cosgrove K. Higher drinking frequency corresponds to lower synaptic density in people with alcohol use disorder. Journal Of Clinical Investigation 2026, 136: e199989. PMID: 41528802, PMCID: PMC13038192, DOI: 10.1172/jci199989.Peer-Reviewed Original ResearchThis study investigates how chronic alcohol use reduces brain synaptic density in key regions, linking greater drinking frequency to more severe synaptic deficits and cognitive impairments.
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, 183: 58-69. PMID: 41366835, DOI: 10.1176/appi.ajp.20241084.Peer-Reviewed Original ResearchAutistic adults have lower levels of a key brain receptor linked to excitatory activity, suggesting a molecular basis for altered brain function in autism.Imaging Neuroimmune Dysfunction: From TSPO to Emerging Positron Emission Tomography Targets
Bonomi R, Raval N, Hillmer A, Cosgrove K. Imaging Neuroimmune Dysfunction: From TSPO to Emerging Positron Emission Tomography Targets. Biological Psychiatry 2025, 99: 1013-1024. PMID: 41297785, DOI: 10.1016/j.biopsych.2025.11.010.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsCitationsAltmetricExceptional 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, 53: 2110-2121. PMID: 41177836, PMCID: PMC12860869, DOI: 10.1007/s00259-025-07605-4.Peer-Reviewed Original ResearchCitationsAltmetricCarotid 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 ResearchCitationsAltmetricCannabinoid 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.Peer-Reviewed Original ResearchCitationsAltmetricGreater 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 ResearchCitationsAltmetric
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News
- January 20, 2026
Yale Study: Higher Drinking Frequency Corresponds to Lower Synaptic Density in People with Alcohol Use Disorder
- 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
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