Cellular and Molecular Biology of Complex Brain Disorders (R21 Clinical Trial Not Allowed) | PAR 20 264

Opportunity Information: Apply for PAR 20 264

The National Institutes of Health funding opportunity PAR-20-264, titled "Cellular and Molecular Biology of Complex Brain Disorders (R21 Clinical Trial Not Allowed)," supports exploratory, early-stage projects that dig into how well-supported (high-confidence) risk factors actually affect the brain at a biological level. The emphasis is on understanding neural function through intracellular mechanisms (what happens within cells), transcellular mechanisms (how cells influence each other), and circuit-level substrates (how networks of neurons and supporting cells produce function). Here, "complex brain disorders" is used in a broad way and can mean disorders driven by many interacting influences such as multiple genes and/or environmental exposures, and/or disorders whose dysfunction is distributed across many brain regions and systems rather than localized to one spot.

The central goal is not to recreate or model an entire disorder in an organism or system, but to isolate and clarify what specific risk factors do to neurobiology. Applicants are encouraged to focus on individual risk factors or combinations of risk factors and map how these alter molecular pathways, cellular components, synaptic functions, and circuit-relevant biological processes. This can include foundational work on the basic biology of implicated genes, proteins, cellular structures, or regulatory processes, as long as it helps connect risk factors to mechanisms that could later inform therapeutic target discovery. Projects can be hypothesis-generating (for example, unbiased discovery approaches that screen for pathway changes) or hypothesis-testing (directly evaluating predicted mechanisms), and can use in vivo, in situ, or in vitro paradigms. The FOA explicitly allows common experimental platforms in neuroscience and neurobiology, including model organisms and human cell-based systems such as cultured cells and other assay formats.

Behavioral testing is optional rather than expected. Applicants may include behavioral paradigms or behavioral outcome measures if they genuinely help connect molecular or cellular findings to circuit mechanisms, but the FOA makes clear that behavior is not the main deliverable. Instead, reviewers are likely to focus on whether the project produces interpretable mechanistic insight into how risk factors reshape cellular and circuit biology, and whether it produces approaches, datasets, or mechanistic descriptions that help close the gap between genetic or environmental risk and actionable biology.

A notable expectation in this announcement is dissemination in a way that strengthens shared scientific resources. The NIH is signaling that resulting experimental paradigms, component pathways, and defined biological processes should be described with enough precision and structure that they can feed into common or federated data ecosystems. Examples named in the FOA include the Gene Ontology, Synaptic Gene Ontology, and FAIR-aligned data informatics efforts. In practice, this means applicants should think not only about producing results, but also about how they will represent pathways, processes, and components in standardized, reusable formats that other researchers and databases can incorporate, making it easier for the field to translate risk-factor knowledge into mechanistic frameworks and potential targets.

This is an R21 mechanism, which generally aligns with high-risk, high-reward, early or exploratory work rather than large, mature programs of research. The opportunity has an award ceiling listed at $200,000 (as provided in the source data) and is categorized as a discretionary grant in the health funding activity area (CFDA 93.242). Clinical trials are not allowed under this FOA, meaning the work must remain on the preclinical or basic/mechanistic side rather than testing interventions in human participants as a clinical trial.

Eligibility is broad and includes many types of U.S. organizations and some non-U.S. entities. Eligible applicants include public and private institutions of higher education, nonprofits (with or without 501(c)(3) status), for-profit organizations (other than small businesses), small businesses, and various government entities (state, county, city/township, special district, independent school districts), as well as federally recognized Native American tribal governments and other tribal organizations. The FOA also highlights eligibility for a range of institution types and communities, including Alaska Native and Native Hawaiian Serving Institutions, AANAPISI institutions, Hispanic-serving institutions, HBCUs, tribally controlled colleges and universities, faith-based or community-based organizations, U.S. territories or possessions, regional organizations, and foreign (non-U.S.) organizations. The sponsoring agency is the National Institutes of Health, and the original closing date listed in the source data is 2023-07-17.

In summary, PAR-20-264 is aimed at sharpening the mechanistic link between established risk factors and the cellular/circuit biology of brain disorders, using flexible experimental systems and either discovery or hypothesis-driven designs. The strongest fits are projects that can clearly define how a risk factor perturbs specific molecular and cellular components, show how those perturbations relate to neural communication or circuitry, and package the resulting knowledge in a form that can be reused by the broader neuroscience community to accelerate mechanism-to-target progress.

• The National Institutes of Health in the health sector is offering a public funding opportunity titled "Cellular and Molecular Biology of Complex Brain Disorders (R21 Clinical Trial Not Allowed)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.242.
• This funding opportunity was created on 2020-08-10.
• Applicants must submit their applications by 2023-07-17. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Each selected applicant is eligible to receive up to $200,000.00 in funding.
• Eligible applicants include: State governments, County governments, City or township governments, Special district governments, Independent school districts, Public and State controlled institutions of higher education, Native American tribal governments (Federally recognized), Public housing authorities/Indian housing authorities, Native American tribal organizations (other than Federally recognized tribal governments), Nonprofits having a 501 (c) (3) status with the IRS, other than institutions of higher education, Nonprofits that do not have a 501 (c) (3) status with the IRS, other than institutions of higher education, Private institutions of higher education, For-profit organizations other than small businesses, Small businesses, Others.

Apply for PAR 20 264

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