About

Barnett Schlinger is a professor in the Department of Integrative Biology and Physiology at UCLA College Life Sciences. His research focuses on the actions of steroids on the central nervous system developmentally and in adulthood, with particular emphasis on estrogen synthesis and metabolism in the brain. His lab explores sex steroid synthesis, especially the enzyme aromatase that converts androgens into estrogens, demonstrating its expression and activity across diverse species and functions. Schlinger's work has documented the role of neuroestrogens in neuronal development, neural repair, behaviors such as sexual and aggressive actions, learning, memory, and auditory processing. He has contributed to the understanding of neurosteroidogenesis, investigating whether steroids can be synthesized de novo in the brain and whether these neurosteroids are functional. His research extends into the physiology of elaborate animal courtship, notably using the golden-collared manakin as a model to study hormonal, neural, and muscular control of complex behaviors. His work in this area has revealed unique anatomical and physiological specializations and has supported the concept of functional neurosteroidogenesis, broadening the understanding of hormonal control in natural animal behaviors. Schlinger’s research integrates tropical field behavioral ecology with molecular, cellular, and organ-level physiology, and he has been involved in sequencing the genome of the manakin to facilitate molecular genetic studies of social systems and behavior.

Research topics

• Evolutionary biology
• Biology
• Psychology
• Neuroscience
• Genetics
• Computational biology
• Ecology
• Cognitive science
• Communication

Selected publications

• Endocrine and skeletal muscle physiology optimizing avian migratory capabilities

  Journal of Avian Biology · 2025-11-01 · 2 citations

  articleOpen access1st author

  The long‐distance migrations of thousands of bird species and their billions of individuals are feats of astounding physiological specialization and plasticity. Whereas numerous organ systems require modification to achieve successful fueling and navigation capabilities, given their overarching importance for movement and contribution to body mass, skeletal muscles are subject to exceptional performance optimization and anatomical plasticity. To express the appropriate changes throughout the complicated life history of migration, while remaining in synchrony with the environment, skeletal muscles must receive preparatory signals and express transcriptional and biochemical modifications required for full expression of the migratory phenotype. In all likelihood, these muscles must also temporally signal their state and needs to other organ systems. By considering other well‐studied avian skeletal muscle systems, this review explores how endocrine signaling likely impacts skeletal muscles involved in migration and, conversely, how those muscles might relay their condition elsewhere throughout the bird's body. Systems biology offers exceptional modeling for capturing this complex biology.

  PublisherOA PDFDOI

• Monocyte Chemoattractant Protein‐1 and its role in Alzheimer’s Disease: A Longitudinal Study

  Alzheimer s & Dementia · 2025-12-01

  articleOpen access

  BACKGROUND: Neuroinflammation and systemic inflammation are increasingly studied in Alzheimer's disease (AD) pathogenesis. Monocyte Chemoattractant Protein-1 (MCP-1), a mediator of both processes, has demonstrated variable prognostic value depending on disease stage. To clarify its role in early AD, this study examines baseline MCP-1 levels in cerebrospinal fluid (CSF) and plasma in individuals with mild cognitive impairment (MCI), assessing associations with FDG-PET imaging outcomes over three years. METHOD: Imaging, demographic, and biomarker data were obtained from the Alzheimer's Disease Neuroimaging Initiative for 97 individuals with MCI (MMSE = 27.4 ± 1.58; CDRSB = 1.54 ± 0.78), totaling 184 FDG-PET scans at baseline and three-year follow-up. Plasma and CSF MCP-1 levels were measured via multiplex assay with analyte-specific quality control. Concentrations, originally pg/mL, were log-transformed for statistical analyses. FDG-PET scans were co-registered and smoothed to 6 mm³. NeuroQ analysis involved scalp removal, rigid registration, and elastic transformation to generate 47 standardized VOIs (sVOIs) normalized to whole-brain metabolism. A general linear model (GLM) assessed longitudinal sVOI changes, adjusting for age, gender, APOE4, and education. RESULT: Imaging analysis identified four sVOIs with significantly greater metabolic decline over three years associated with lower baseline plasma MCP-1 levels. The GLM revealed that for each unit decrease in plasma MCP-1, there was a corresponding reduction in metabolic decline: right posterior temporal cortex (3.3%, 0.033 ± 0.016, p = 0.04), right inferior lateral posterior temporal cortex (3.1%, 0.031 ± 0.014, p = 0.03), right superior lateral temporal cortex (3.9%, 0.039 ± 0.011, p = 0.0003), and right associative visual cortex (3.0%, 0.030 ± 0.013, p = 0.02). In contrast, higher CSF MCP-1 levels were associated with more metabolism over the same period, with the right inferior lateral posterior temporal cortex exhibiting a 9.1% increase (0.091 ± 0.032, p = 0.007). CONCLUSION: Our findings show that lower plasma MCP-1 levels are correlated to a significant decrease in metabolism in regions associated with AD over a three year period, while higher CSF MCP-1 levels are correlated with an increase in metabolism.

  PublisherOA PDFDOI

• Hormonal and neuromuscular regulation of courtship displays

  Elsevier eBooks · 2025-01-01

  book-chapter1st authorCorresponding
  PublisherDOI

• Comparing fear responses of two lizard species across habitats varying in human impact

  Journal of Urban Ecology · 2024-02-01 · 4 citations

  articleOpen access

  Abstract Animals that are successful in urban habitats often have reduced antipredator responses toward people (sometimes called “fear” responses). However, few studies test whether sympatric species differ in their responses to humans, which may explain differing sensitivities to urbanization. Here, we quantified the behavioral and physiological responses to humans in two lizard species, side-blotched lizards (Uta stansburiana) and western fence lizards (Sceloporus occidentalis), across three different habitat types that vary in human impact: natural habitats with low levels of human activity, natural habitats with high levels of human activity, and urban habitats. We found that side-blotched lizards had longer flight initiation distances, were found closer to a refuge, and were more likely to hide than fence lizards, behaviors that could indicate greater fearfulness. Both lizard species were found closer to a refuge and were also more likely to hide in the urban habitat than in the natural habitat with low human impact, which could represent adaptive behaviors for increased risks in urban areas (e.g. cats). Western fence lizards exhibited lower body sizes and conditions in the habitats with moderate and high levels of human activity, whereas these traits did not differ among habitats in side-blotched lizards. Baseline and stress-induced corticosterone concentrations did not differ across habitats for both species, suggesting that human-impacted habitats were not stressful or that lizards had undergone habituation-like processes in these habitats. Taken together, our results highlight the importance of standardized measurements across multiple species in the same habitats to understand differential responses to human-induced environmental change.

  PublisherOA PDFDOI

• Behavioral Endocrinology and Vertebrate Sex Differences

  Yale University Press eBooks · 2023-09-05

  book-chapter1st authorCorresponding

  Basic principles of endocrinology, sex determination, and sexual differentiation underlie many facets of manakin biology: hormones, which, coordinate the functions of multiple organ systems: steroids, which play a special role in regulating reproductive processes, including behavior; tissues, which can be involved in regulating complex molecular events within cells. In some cases, hormonal exposure leads to sex-specific phenotypes. The sexes differentiate early in fetal development based, at least in mammals and birds, on chromosomal composition. Sex-specific chromosomes then guide gonadal development, and the gonads secrete hormones, including steroids, to guide the formation of anatomical features appropriate for the gonad that is present. Some tissues do develop sexual phenotypes independent of hormones likely owing to the action of the sex chromosomes present in cells of that tissue. This latter mechanism is easily observed in birds called gynandromorphs that are laterally sexually dimorphic.

  PublisherDOI

• Beyond plumage: acrobatic courtship displays show intermediate patterns in manakin hybrids

  Animal Behaviour · 2023-03-10 · 7 citations

  article
  PublisherDOI

• THIRTEEN Females Shape Male Manakin Behavior

  Yale University Press eBooks · 2023-10-13

  book-chapter1st authorCorresponding
  PublisherDOI

• Male Manakins Are Made to Snap

  Yale University Press eBooks · 2023-09-05

  book-chapter1st authorCorresponding

  The mechanics of making loud wingsnapping sounds involve specializations of the male manakin’s wing bones and muscles. Avian wing bones are described as well as micro-CT studies of manakin wings that show the radius of wingsnapping birds to be flattened relative to the rounded radius of other birds. <italic>Manacus</italic> radius bones are also mostly solid as compared to the radius of other birds with a mostly hollow radius. EMG recordings of male golden-collared manakins producing wingsnaps show that the dorsal scapulohumeralis (SH) muscle contracts rapidly and powerfully to pull the wings together to create the snap. This muscle is enlarged in male manakins relative to other birds. This muscle in male manakins was also shown by biochemical and physiologic measures to be a “superfast” muscle. Other manakin specializations that assist the production of courtship postures and sounds associated with their lek mating system are described.

  PublisherDOI

• SIX Research in Field and Laboratory

  Yale University Press eBooks · 2023-10-13

  book-chapter1st authorCorresponding
  PublisherDOI

• Research in Field and Laboratory

  Yale University Press eBooks · 2023-09-05

  book-chapter1st authorCorresponding

  Much research on birds is observational, but studies of physiology sometimes require a bird to be killed. The author reviews his own personal history as a biologist, which includes discussion of the way that love and respect for an animal is intermingled with the desire to know the animal’s biology better.

  PublisherDOI

Recent grants

• NIH Grant R03AG016145

  NIH · $76k · 2000

• Hormonal Control of an Avian Neuromuscular System

  NSF · $400k · 2012–2018

• Hormonal Control of an Avian Neuromuscular System

  NSF · $355k · 2002–2006

• NIH Grant R01MH061994

  NIH · $4.1M · 2015

• Hormonal Control of an Avian Neuromuscular System

  NSF · $300k · 2007–2012

Frequent coauthors

• Matthew J. Fuxjager

  Providence College

  44 shared

• Leonida Fusani

  39 shared

• Lainy B. Day

  University of Mississippi

  27 shared

• Colin J. Saldanha

  American University

  26 shared

• Arthur P. Arnold

  University of California, Los Angeles

  20 shared

• Luke Remage‐Healey

  University of Massachusetts Amherst

  18 shared

• Julia Barske

  University of California, Los Angeles

  17 shared

• Kiran K. Soma

  University of British Columbia

  17 shared