Rebecca Knickmeyer

Contact

knickmey@msu.edu
Office:  517-355-3977
Lab:  517-355-3978
IQ DIVISION – Neuroengineering

Departmental AFFILIATIONS

• Pediatrics

About

Rebecca Knickmeyer is an Associate Professor in the Department of Pediatrics and Human Development within the College of Human Medicine. Her research focuses on understanding how genetic and environmental factors influence the development of brain morphometry, anatomical and functional connectivity, and cognitive and emotional function in infancy and early childhood. She has a particular interest in mechanisms underlying sexual differentiation of the brain and the microbiome-gut-brain axis. Dr. Knickmeyer received her Ph.D. in Experimental Psychology from the University of Cambridge (U.K.) and completed her postdoctoral training in the Neurodevelopmental Disorders Research Center at the University of North Carolina at Chapel Hill.

The Knickmeyer Lab

At present, there are no cures for psychiatric conditions such as schizophrenia and major depression. While pharmacological and psychosocial interventions can be very helpful, by the time clinical symptoms appear, substantial alterations in brain development have already occurred and may be difficult or impossible to reverse. Therefore, our best hope of making a major impact on these disorders is through prevention and very early intervention. Infancy and early childhood represent a particularly promising period for intervention, as this is the most plastic phase of postnatal human development, marked by explosive brain growth, the emergence of functional brain networks, and dramatic advances in cognitive ability and behavioral repertoire.

The long-term goal of the Knickmeyer lab is to develop therapeutic interventions to adjust adverse neurodevelopmental trajectories in infancy and early childhood, thereby preventing the onset of psychiatric disorders or reducing their severity. Our immediate goal is to identify genes and molecular pathways associated with altered brain development in infancy and early childhood through the integration of pediatric neuroimaging with cutting-edge techniques in genomics, metagenomics, and analytical chemistry.

Our work also addresses the origins of neurodevelopmental conditions including autism and attention-deficit hyperactivity disorder. These complex and heterogeneous conditions include both differences (e.g. personality and preferences) and disabilities (e.g. anxiety, gastrointestinal problems, self-harm). Our goal in understanding how these conditions manifest in early life is to allow for early identification, earlier accessing of resources and neurodiversity-friendly environments, and early application of ethical interventions focused on the disabling aspects, not on differences.

Major areas of research

Influence of the Gut Microbiota on Infant Brain Development

The gut microbiome is a complex microbial ecosystem that varies between individuals and may influence neurodevelopment. Projects in this area use gnotobiotic mice, human clinical samples, neuroimaging, and neurobehavioral techniques to understand how microbes contribute to risk for anxiety, depression, and disabling aspects of autism spectrum conditions, especially GI issues. We are also actively studying whether the microbiome mediates the impact of prenatal stress and chemical exposures on cognitive development in childhood.

Genetic Influences on Infant Brain Development

Imaging-genetics represents a powerful strategy for understanding how genetic variants impact neural structure and function, producing individual differences in psychiatric risk. Large-scale cross-sectional studies in adolescents and adults are demonstrating the power of this framework but cannot fully address the reality that mental illnesses are unfolding developmental processes, which commence in prenatal life and have different consequences at different life stages. The Knickmeyer lab is addressing this challenge by assembling a large and well-characterized imaging-genomics dataset focused on infancy, via collaborations with world-leaders in infant neuroimaging. We call this effort ORIGIN (Organization for Imaging Genomics of Infancy), and it is a working group of the ENIGMA consortium (Enhancing Neuro Imaging Genetics through Meta-Analysis). Specific goals include:

•  Identify genes influencing neurodevelopmental trajectories from birth to age six using univariate and multivariate GWAS approaches.
• Develop predictive models for cognitive ability and emotional functioning using genetic variation, environmental risk factors, and neuroimaging phenotypes.
• Clarify how genes associated with psychiatric disorders and neurodevelopmental conditions influence brain development in infancy and early childhood.

Sexual Differentiation of the Human Brain:

Relative risk levels for many psychiatric disorders differ in males and females. In addition, autism and ADHD appear to be more common in males and may look different in females. X-chromosome effects and early exposure to gonadal hormones (especially androgens and estrogens) are strong candidates for a causal role. Projects in this area include neuroimaging studies of typical children and individuals with Turner syndrome (TS), a well-defined genetic condition resulting from partial or complete loss of one of the sex chromosomes.