About

Professor Karla Kaun leads the Kaun Lab at Brown University, focusing on the behavioral neurogenetics of addiction. The lab studies the genetic, neural, and molecular mechanisms underlying memory, reward, and addiction. Their research utilizes the fruit fly, Drosophila melanogaster, as a model organism to investigate these complex biological processes. This approach allows for detailed exploration of the fundamental pathways involved in addiction and related behaviors.

Research topics

• Genetics
• Biology
• Neuroscience
• Medicine
• Cell biology
• Botany
• Psychology

Selected publications

• Data for Characterizing Choice Behavior in Drosophila Olfactory Classical Conditioning

  Open MIND · 2026-02-03

  datasetOpen accessSenior author
  OA PDFDOI

• Investigating pharmacotherapies for alcohol use disorder using <i>Drosophila melanogaster</i>

  Alcohol Clinical and Experimental Research · 2025-09-29

  articleOpen accessSenior authorCorresponding

  BACKGROUND: Drosophila melanogaster provides a powerful whole-organism approach for the therapeutic discovery of treatments for many disorders due to the ability to perform high-throughput drug studies with detailed molecular and cellular mechanisms. While Drosophila has been critical for identifying novel molecular and neural circuit mechanisms underlying alcohol responses, few studies assess the use of Drosophila for the investigation and discovery of pharmacological targets of alcohol use disorder (AUD). Determining appropriate doses that impact alcohol consumption and memory for alcohol reward without affecting acute locomotor responses is key to identifying effective AUD medications such as naltrexone, acamprosate, and topiramate. This pipeline can then be used to test novel pharmacotherapies, including γ-secretase inhibitors (such as dibenzazepine and compound E) as potential treatments for AUD. METHODS: To validate Drosophila as an effective model for studying pharmacological therapies for AUD, we identified nondisruptive drug doses in flies using feeding and locomotive assays. Then, we assessed their impact on ethanol consumption and conditioned preference in cue-induced alcohol-seeking after 1 or 3 days of training. RESULTS: Naltrexone and acamprosate significantly reduced ethanol food preference and 3-day conditioned preference, while topiramate did not. γ-secretase inhibitors dibenzazepine and compound E significantly decreased conditioned preference after 3 days. CONCLUSION: Drosophila is a valuable model organism for identifying and characterizing new AUD pharmacotherapies.

  PublisherOA PDFDOI

• Hunger Recruits a Parallel Circuit Encoding Alcohol Reward

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-10-15

  preprintOpen accessSenior authorCorresponding

  Summary Internal states like hunger, pain, thirst and arousal can bias behavior by affecting sensory and memory processing. Internal states are critical to understand in the context of alcohol addiction because they influence cravings, reinstatement, and relapse. Norepinephrine plays a key role in both hunger and alcohol-induced arousal and preference, but the circuit-level mechanisms through which it modulates the influence of hunger on alcohol preference are not well understood. We sought to address this using intersectional genetic tools for manipulating neurons expressing octopamine, the invertebrate analogue of vertebrate norepinephrine. We identified a single octopamine neuron required for ethanol seeking only when Drosophila are food-deprived. Hunger increased baseline activity in this neuron, making it more responsive to an odor cue previously paired with ethanol. A combination of genetic and connectome analyses revealed that synaptic partners of this octopaminergic neuron form a functional module that acts on Drosophila memory circuitry. Thus, we show that hunger recruits a parallel circuit that drives learned ethanol preference, providing a neuronal framework through which internal state influences the expression of memory for ethanol-associated cues.

  PublisherOA PDFDOI

• Shaping of olfactory responses by taste in a new assay for operant learning in <i>Drosophila melanogaster</i>

  Journal of Experimental Biology · 2025-10-22 · 1 citations

  articleOpen accessSenior author

  Animals are driven to maximize food rewards and adjust their behavior to seek high-quality food and avoid low-quality options. This holds true for Drosophila melanogaster, which approaches food-associated odors and tastes while avoiding aversive ones. Despite its importance for understanding motivation, how voluntary olfactory and gustatory experiences shape fly interactions with these stimuli over time remains unclear. Here, we investigate how stimuli shape volitional behavior using our novel operant learning assay (Open-LA), which tracks individual flies as they enter/exit a region of stimuli self-administration. We analyzed the behaviors flies demonstrated when they control access to an aversive or appetitive odor or taste and analyzed how these behaviors were shaped by experience. As predicted, flies pursued apple cider vinegar and avoided benzaldehyde and showed rapid operant learning for both odors. Flies also self-administered both simulated sweet and bitter taste, which slightly altered aversive odor responses, but did not strongly enhance odor-based operant learning. These data suggest olfaction is the primary sense guiding volitional behaviors and provides a behavioral framework for examining how animals pursue positive and avoid negative stimuli.

  PublisherOA PDFDOI

• Neuroscientists need to do better at explaining basic mental health research

  The Transmitter · 2025-01-01

  article
  PublisherDOI

• What do the mushroom bodies do for the insect brain? Twenty-five years of progress

  Learning & Memory · 2024-05-01 · 12 citations

  editorialOpen accessSenior author

  was published with a discrete focus of synthesizing the state of the field to provide an overview of the function of the insect mushroom body. While molecular neuroscience and optical imaging of larger brain areas were advancing, understanding the basic functioning of neuronal circuits, particularly in the context of the mushroom body, was rudimentary. In the past 25 years, technological innovations have allowed researchers to map and understand the in vivo function of the neuronal circuits of the mushroom body system, making it an ideal model for investigating the circuit basis of sensory encoding, memory formation, and behavioral decisions. Collaborative efforts within the community have played a crucial role, leading to an interactive connectome of the mushroom body and accessible genetic tools for studying mushroom body circuit function. Looking ahead, continued technological innovation and collaborative efforts are likely to further advance our understanding of the mushroom body and its role in behavior and cognition, providing insights that generalize to other brain structures and species.

  PublisherOA PDFDOI

• Alcohol and drugs rewire your brain by changing how your genes work – research is investigating how to counteract addiction’s effects

  2024-01-22

  articleOpen access1st authorCorresponding
  PublisherDOI

• Dopamine determines how reward overrides risk

  Nature · 2023-10-25 · 1 citations

  articleOpen accessSenior authorCorresponding
  PublisherOA PDFDOI

• Ethanol Behavioral Responses in<i>Drosophila</i>

  Cold Spring Harbor Protocols · 2023-04-05 · 6 citations

  articleOpen accessSenior author

  is a powerful genetic model for investigating the mechanisms underlying ethanol-induced behaviors, metabolism, and preference. Ethanol-induced locomotor activity is especially useful for understanding the mechanisms by which ethanol acutely affects the brain and behavior. Ethanol-induced locomotor activity is characterized by hyperlocomotion and subsequent sedation with increased exposure duration or concentration. Locomotor activity is an efficient, easy, robust, and reproducible behavioral screening tool for identifying underlying genes and neuronal circuits as well as investigating genetic and molecular pathways. We introduce a detailed protocol for performing experiments investigating how volatilized ethanol affects locomotor activity using the fly Group Activity Monitor (flyGrAM). We introduce installation, implementation, data collection, and subsequent data-analysis methods for investigating how volatilized stimuli affect activity. We also introduce a procedure for how to optogenetically probe neuronal activity to identify the neural mechanisms underlying locomotor activity.

  PublisherOA PDFDOI

• Drosophila Reward Circuits

  Oxford Research Encyclopedia of Neuroscience · 2023-08-21 · 6 citations

  reference-entrySenior author

  The ability to sense and respond to a rewarding stimulus is a key advantage for animals in their natural environment. The circuits that mediate these responses are complex, and it has been difficult to identify the fundamental principles of reward structure and function. However, the well-characterized brain anatomy and sophisticated neurogenetic tools in <italic>Drosophila melanogaster</italic> make the fly an ideal model to understand the mechanisms through which reward is encoded. <italic>Drosophila</italic> find food, water, intoxicating substances, and social acts rewarding. Basic monoaminergic neurotransmitters, including dopamine (DA), serotonin (5-HT), and octopamine (OA), play a central role in encoding these rewards. DA is central to sensing, encoding, responding, and predicting reward, whereas 5-HT and OA carry information about the environment that influences DA circuit activity. In contrast, slower-acting neuromodulators such as hormones and neuropeptides play a key role in both encoding the pleasurable stimulus and modulating how the internal environment of the fly influences reward sensation and seeking. Recurring circuit motifs for reward signaling identified in <italic>Drosophila</italic> suggest that these key principles will help elucidate understanding of how reward circuits function in all animals.

  PublisherDOI

Recent grants

• Notch-dependent microcircuit regulation of alcohol reward memory

  NIH · $3.9M · 2016–2026

• Administrative Core

  NIH · $46.6M · 2013–2025

Frequent coauthors

• Kristin M. Scaplen

  Bryant University

  39 shared

• Reza Azanchi

  Providence College

  35 shared

• Ulrike Heberlein

  Janelia Research Campus

  35 shared

• Jamie L. Catalano

  Children's Hospital of Philadelphia

  22 shared

• Kavin M. Nuñez

  New York University

  21 shared

• Emily Petruccelli

  Southern Illinois University Edwardsville

  20 shared

• Mustafa Talay

  18 shared

• Sophia Song

  European Aquaculture Society

  17 shared

Labs

• Kaun LabPI

Education

• Ph.D., Neuroscience

  Brown University

  2005

• B.S., Neuroscience

  University of California, San Diego

  1999

Awards & honors

• Smith Family Award for Excellence in Biomedical Research (20…
• Named Robert J. and Nancy D. Carney Assistant Professor of N…
• International Behavioral and Neural Genetics Society Young I…
• President, International Behavioral and Neural Genetics Soci…
• Genetics Education Award from the National Association of Bi…