A systematic-review of olfactory deficits in neurodevelopmental disorders: From mouse to human

•Hyposmia is a common feature of neurodevelopmental and neurodegenerative disorders.•The buried food test is the most commonly used assay of olfactory function in mice.•Olfactory testing is more commonly performed in mouse models of Autism than other neurodevelopmental disorders.•Olfactory testing in mouse models of Autism it is less likely to be abnormal than olfactory testing in other neurodevelopmental disorders.•Rigorous and uniform olfactory testing in models of neurological disease is needed. Olfactory impairment is a common clinical motif across neurodevelopmental disorders, suggesting olfactory circuits are particularly vulnerable to disease processes and can provide insight into underlying disease mechanisms. The mouse olfactory bulb is an ideal model system to study mechanisms of neurodevelopmental disease due to its anatomical accessibility, behavioral relevance, ease of measuring circuit input and output, and the feature of adult neurogenesis. Despite the clinical relevance and experimental benefits, olfactory testing across animal models of neurodevelopmental disease has been inconsistent and non-standardized. Here we performed a systematic literature review of olfactory function testing in mouse models of neurodevelopmental disorders, and identified intriguing inconsistencies that include evidence for both increased and decreased acuity in odor detection in various mouse models of Autism Spectrum Disorder (ASD). Based on our identified gaps in the literature, we recommend direct comparison of different mouse models of ASD using standardized tests for odor detection and discrimination. This review provides a framework to guide future olfactory function testing in mouse models of neurodevelopmental diseases.