Operant Platform
Neuropsychiatric and neurological disorders are ultimately expressed through changes in behavior, cognition, motivation, and decision-making, yet many promising drug candidates fail in clinical development because preclinical testing does not adequately capture the complex behavioral domains that drive patient outcomes. As the field moves beyond traditional symptom management toward mechanism-driven therapeutics, there is a growing need for translational platforms that can bridge the gap between preclinical efficacy and clinical success.
Transpharmation has developed a world-class rodent operant platform that enables the assessment of discrete, clinically relevant behavioral and cognitive constructs and domains, including attention, motivation, motor behavior, motor impulsivity, choice impulsivity, compulsive behavior, anxiety-related behavior, and reward processing, as well as the assessment of drug-induced interoceptive states through drug discrimination. Using highly sensitive operant tasks, our platform can detect subtle yet meaningful changes in behavioral performance that are often missed by conventional assays. By deconstructing complex disorders into measurable behavioral and cognitive domains, we help sponsors identify, de-risk, and prioritize promising therapeutic candidates while generating robust translational data to support critical go/no-go decisions throughout drug development.
Beyond our established assay portfolio, we frequently collaborate with sponsors to co-develop customized behavioral paradigms tailored to specific mechanisms of action, therapeutic hypotheses, or target indications. This flexible and scientifically rigorous approach allows sponsors to maximize the value of their emerging NCEs and gain deeper insights into therapeutic efficacy before entering costly clinical trials.
Operant assays
Delayed Matching/Non-Matching-to-Position (DMTP/DNMTP) is a highly translational assay of working memory with strong relevance to human cognitive tests such as CANTAB® Spatial Working Memory, Delayed Match-to-Sample, and N-Back paradigms. Animals are required to remember the location of a previously presented stimulus over a delay period and subsequently select either the same location (DMTP) or a different location (DNMTP) to obtain a reward. The assay demonstrates sensitivity to the muscarinic receptor antagonist scopolamine, a widely used pharmacological model of cognitive dysfunction that produces deficits in working memory in both preclinical models and human studies.
Read the full description: Delayed Matching/Non-Matching to Position Task
The 5-Choice Serial Reaction Time Task (5-CSRTT) has strong translational relevance to clinically used Continuous Performance Tests (CPTs), which are widely used to assess attention, vigilance, and inhibitory control in human subjects. Animals are trained to detect and respond to brief visual stimuli presented unpredictably across five spatial locations to obtain a reward. The 5-CSRTT also enables behavioral stratification into distinct endophenotypes, such as high- and low-attentive or highly and minimally impulsive animals. The 5-CSRTT demonstrates sensitivity to clinically established ADHD therapies, including atomoxetine (Strattera®), methylphenidate (Ritalin®), amphetamine (Adderall®) and guanfacine (Intuniv®).
Read the full description: 5-Choice Serial Reaction Time Task
Differential Reinforcement of Low Rates (DRL) is an operant assay used to assess impulsive action, behavioral inhibition, timing, and response control. Animals must withhold responding for a defined period before making a response to obtain a reward, providing a direct measure of their ability to inhibit premature actions. The DRL assay is sensitive to atomoxetine, a clinically approved treatment for ADHD, supporting its translational validity as a platform for assessing impulsive action and behavioral inhibition.
Read the full description: Differential Reinforcement of Low Rates Task
Conditioned Emotional Responding (CER) has strong translational relevance to human fear-conditioning and fear-extinction paradigms commonly used to study anxiety disorders, PTSD, and stress-related disorders. Animals are first trained to perform an operant response for reward, after which a previously neutral stimulus is paired with an aversive event. The subsequent presentation of this conditioned stimulus suppresses reward-seeking behavior, providing a sensitive and quantitative measure of conditioned fear and emotional responding. The CER assay is sensitive to standard-of-care anxiolytics, including diazepam, supporting its translational validity and utility for screening novel anxiolytic compounds.
Read the full description: Conditioned Emotional Response Task
Schedule-Induced Polydipsia (SIP) is an operant model used to assess compulsive behavior, habit formation, and behavioral inflexibility. Animals develop excessive, non-homeostatic drinking behavior in response to intermittent reward schedules, providing a sensitive measure of repetitive and compulsive actions that share similarities with behavioral domains affected in disorders such as obsessive-compulsive disorder (OCD), schizophrenia, and substance use disorders. SIP demonstrates sensitivity to clinically effective anti-compulsive treatments, including the SSRI citalopram, a first-line therapy for OCD.
Effort-Based Food Choice (EBFC) is a highly translational behavioral assay used to assess motivation, effort allocation, reward valuation, and goal-directed behavior. In this task, animals choose between a high-value reward that requires effort to obtain and a lower-value reward that is freely available. The assay demonstrates sensitivity to tetrabenazine, a vesicular monoamine transporter-2 (VMAT2) inhibitor that induces motivational deficits and effort-related impairments. Tetrabenazine shifts behavior away from high-effort/high-reward options toward freely available or low-effort alternatives, mirroring motivational impairments observed in clinical populations.
Progressive Ratio (PR) is a highly translational operant assay used to assess motivation, reward valuation, and willingness to exert effort for reward. In this task, the number of responses required to obtain each successive reward progressively increases, allowing investigators to determine the maximum amount of effort an animal is willing to expend to obtain a desired outcome. The highest ratio completed, known as the breakpoint, is widely recognized as a sensitive measure of motivation and reward-seeking behavior. The assay demonstrates sensitivity to bupropion, a clinically used norepinephrine-dopamine reuptake inhibitor that increases effortful responding and motivation-related behavior.
Delay Discounting has direct cross-species relevance because the same behavioral paradigm is used in both rodents and humans. Animals are repeatedly given a choice between a small immediate reward and a larger delayed reward, providing a quantitative measure of their willingness to wait for greater future outcomes. Preference for smaller immediate rewards is interpreted as increased impulsive choice, a behavioral phenotype commonly observed across several neuropsychiatric disorders.
The Go/No-Go Task is a highly translational operant assay that provides a robust assessment of response inhibition and impulsivity. Animals are trained to respond appropriately to “Go” signals while suppressing responses to “No-Go” signals, enabling precise measurement of inhibitory control and behavioral regulation. The assay demonstrates sensitivity to clinically effective ADHD treatment, atomoxetine, supporting its pharmacological validation and translational utility for evaluating therapies targeting inhibitory control and impulsive behavior.
The Drug Discrimination Task is a highly translational operant assay used to evaluate the interoceptive (internal) cueing properties of drugs and to characterize their pharmacological mechanisms of action. Animals are trained to recognize and discriminate the unique internal cues produced by a reference compound from those produced by vehicle treatment. Because different pharmacological classes and receptor systems produce distinct subjective cue profiles, Drug Discrimination provides a sensitive method for assessing target engagement, mechanism of action, and pharmacological similarity.
The Novel Object Recognition (NOR) test is a widely used assay of non-spatial visual recognition memory that is primarily dependent on perirhinal cortex function. The paradigm exploits rodents’ innate preference for novelty, requiring no prior training or reinforcement, and provides a translational measure of recognition memory that is comparable to cognitive assessments used in humans. During the acquisition phase, animals are exposed to two identical objects, followed by a defined inter-trial interval (ITI). In the test phase, one familiar object is replaced with a novel object, and memory performance is quantified by differential exploration of the two objects using measures including time spent investigating the novel versus familiar object and discrimination index.
The NOR platform enables assessment of distinct memory processes, including encoding, consolidation, and recall, through the manipulation of inter-trial intervals and pharmacological interventions. Short-delay paradigms (e.g., 1-hour ITI) are used to assess cognitive impairment and reversal in disease-relevant models, while extended delays (e.g., 24-hour ITI) provide a sensitive approach for the evaluation of cognition-enhancing compounds.
Transpharmation’s NOR capability incorporates high-throughput multi-box testing configurations within sound-attenuated chambers, ensuring consistent environmental control and reproducible behavioral assessment.
The platform supports a range of pharmacologically validated cognitive impairment models, including subchronic phencyclidine (scPCP) and acute scopolamine challenge paradigms, as well as extended-delay NOR protocols. These models provide sensitivity to both amnestic and pro-cognitive interventions and are applicable to translational research in neurodegenerative, neuropsychiatric, and cognitive disorders, including Alzheimer’s disease and schizophrenia.
Applying the platform across disease areas
Attention-Deficit/Hyperactivity Disorder (ADHD) affects millions of children and adults worldwide and is characterized by deficits in attention, impulse control, and executive function that can significantly impact academic achievement, workplace performance, and quality of life. Although stimulant and non-stimulant medications can be effective for many patients, substantial unmet needs remain, including incomplete symptom control, treatment-limiting side effects, poor treatment adherence, persistent cognitive and executive dysfunction, and the considerable heterogeneity of patient populations. Moreover, despite significant investment in CNS drug discovery, many promising compounds fail during clinical development, highlighting a critical gap in translational predictability between preclinical findings and patient outcomes. As our understanding of ADHD neurobiology expands beyond traditional dopaminergic and noradrenergic mechanisms, there is an urgent need for novel therapeutics and for translationally relevant preclinical assays that can reliably predict clinical efficacy before compounds enter costly clinical trials. Our integrated operant and behavioral neuroscience platform addresses this challenge by assessing core ADHD domains—including attention, impulsivity, cognitive control, and motivation—using clinically relevant, pharmacologically validated assays. These translational tools help sponsors identify, de-risk, and prioritize the most promising therapeutic candidates, increasing confidence in decision-making and improving the likelihood of clinical success.
At Transpharmation, our rodent models are designed to capture the complexity of ADHD across both behavior and underlying biology, helping you build a more complete and translational data package. We apply a range of validated assays and endpoints that reflect key symptoms relevant to both human and animal health:
Behavioral assays
- 5-Choice Serial Reaction Time Task
- Go/No-Go task
- Delay Discounting
- Gambling task
- Differential Reinforcement of Low Rates
- Progressive Ratio
Endpoints and indicators
- Sustained attention and vigilance
- Response accuracy and omissions
- Impulsive action and response inhibition
- Delay tolerance and decision-making
- Working memory and cognitive flexibility
- Motivation and reward valuation
- Effort-based behavior
- Hyperactivity and behavioral regulation
By combining these behavioral and biological measures, you gain robust, decision-ready insights into how your compound performs in rodent models of ADHD—supporting clearer translation into clinical outcomes. Move your ADHD program forward with confidence. Whether you are exploring novel targets or building evidence for clinical translation, our scientists work alongside you to design studies that answer the right questions, early. Talk to a researcher today and see how we can help you generate clear, decision-ready data for your next breakthrough.
Obsessive-Compulsive Disorder (OCD) is a chronic and often disabling psychiatric disorder characterized by intrusive thoughts (obsessions) and repetitive behaviors (compulsions) that can significantly impair daily functioning and quality of life. Although selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy remain the standard of care, many patients experience incomplete symptom relief, persistent compulsive behaviors, treatment resistance, or relapse. In addition, the neurobiology of OCD extends beyond serotonergic pathways and involves dysfunction within cortico-striatal-thalamo-cortical circuits that regulate behavioral inhibition, compulsivity, cognitive flexibility, and decision-making. As novel therapeutic approaches emerge—including glutamatergic, cholinergic, psychedelic, and circuit-based interventions—there is a growing need for translationally relevant preclinical models capable of assessing core OCD-relevant behavioral domains before compounds enter costly clinical trials. Our integrated operant and behavioral neuroscience platform addresses this challenge by quantifying compulsive behavior, cognitive flexibility, response inhibition, habit formation, and decision-making using clinically relevant, pharmacologically validated assays that help sponsors identify, de-risk, and prioritize promising OCD therapies.
Behavioral assays
- 5-Choice Serial Reaction Time Task
- Schedule-Induced Polydipsia
- Reversal Learning
Endpoints and indicators
- Compulsive-like perseverative responding
- Excessive adjunctive behavior
- Cognitive flexibility
Schizophrenia is a complex and highly disabling psychiatric disorder that affects how people think, perceive reality, process information, interact socially, and function in daily life. Although current antipsychotic treatments can help reduce positive symptoms such as hallucinations and delusions, major unmet needs remain for negative symptoms, cognitive impairment, functional disability, and treatment-limiting side effects. Negative symptoms such as reduced motivation, blunted affect, anhedonia, and social withdrawal are strongly associated with poor functional outcomes and respond less well to current medications, while cognitive impairment associated with schizophrenia can affect attention, memory, executive function, occupational performance, social functioning, and treatment adherence.
Despite significant investment in schizophrenia drug discovery, many compounds fail during clinical development because preclinical findings do not always translate well to patient outcomes. This highlights a critical need for mechanism-relevant, clinically informed, and pharmacologically validated translational assays that can assess efficacy across the major schizophrenia symptom domains before compounds advance into costly clinical trials. Our integrated portfolio helps sponsors evaluate positive symptom-relevant phenotypes, negative symptom-related motivation and social behavior, and cognitive domains such as attention, working memory, sensory gating, and executive function, enabling more confident candidate selection and de-risking of novel schizophrenia therapeutics.
Behavioral assays
- Positive symptoms (PPI, ASSR, gamma oscillations)
- Negative symptoms (Progressive Ratio, Social Interaction)
- Cognitive symptoms (Novel Object Recognition, DMTP, 5-Choice)
- Non-drug approaches (DISC1 rat, ARTE10 mice)
Positive symptom-relevant indicators
- Hyperlocomotion
- Stereotypic behavior
- Disrupted sensorimotor gating
- Reversal of MK-801/ketamine/PCP-induced behavioral disruption
- Startle response modulation
- Abnormal response patterns under pharmacological challenge
Negative symptom-relevant indicators
- Reduced motivation
- Lower breakpoint in Progressive Ratio
- Reduced social interaction
- Anhedonia-like reward-processing deficits
Cognitive indicators
- Impaired attention and vigilance
- Increased omissions
- Reduced accuracy
- Impaired working memory
- Reduced cognitive flexibility
- Increased perseverative responding
- Slower or more variable response latency
Translational and pharmacological indicators
- Sensitivity to clinically relevant reference compounds
- Reversal of induced deficits
- Dose-dependent behavioral efficacy
- Cross-assay consistency across cognition, motivation, and sensorimotor gating
- Alignment with clinically relevant symptom domains
- Potential integration with EEG/QEEG biomarker readouts
By combining these behavioral and biological measures, you gain robust, decision-ready insights into how your compound performs in rodent models of schizophrenia—supporting clearer translation into clinical outcomes.
Applicable Portfolio Services
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