Christine  Hohmann

Associate Professor

 

RESEARCH INTERESTS:
Our Developmental Neuroscience laboratory focuses on the ontogeny of cerebral cortex within the context of mental health disorders. We conduct fundamental biomedical and bioenvironmental research, employing mouse models to study brain-behavior relationships, to investigate how developmental disruptions contribute to brain pathologies. Current interests in the lab include Autism Spectrum Disorders (ASD), Depression and related mood disorders, which are both of considerable environmental health significance.

Bioenvironmental Health Relevance:
1) ASD - The frequency of ASD in the population has skyrocketed over the past decades. ASD has it roots in early, perinatal brain development and is currently diagnosed solely based on behavioral criteria, within the first 2 years of childhood. While there are clearly genetic vulnerabilities that increase the susceptibility to ASD in some individuals, the rapid increase in ASD can only be accounted for by environmental factors. As ASD likely encompasses more then one etiology, a number of different environmental factors may play a role. Within this context, our lab is particularly interested in environmental factors tha impact the neurotransmitter serotonin. Our research has demonstrated, that selective, neonatal depletion of serotonin in the neocortex of mice results in morphological changes in the brain, which resemble neuropathologies seen in ASD; simultaneously, social behavioral development is altered, along with an increase in anxiety and novelty aversion, all criteria of the behavioral ASD phenotype. Numerous environmental toxins, as well as psychosocial and physiological stressors have the ability to alter serotonergic function in the developing brain. In future studies we hope to explore some of these factors.

2) Major depressive disorder and related mood disorders, such as anxiety, are associated with alterations in the Hypothalamic-Pituitary-Axis (HPA) mediated stress responsiveness. However, the underlying neurobiological mechanisms are not well understood. Our laboratory has developed a mouse model to study the effects of early life psycho-social and physiological stress on the development of the brain, particularly the neocortex, in conjunction with behavioral development. We have shown, that neonatal stress exposure, in our mice, results in the altered ontogeny of social behavior and leads to altered brain plasticity by adulthood. We are currently pursuing the specific neurobiological mechanisms that may be responsible for these morphological and behavioral effects of early stress exposure.


Health Disparities and Urban Health Significance:

Mental Health Disorders disproportionably affect minority populations, including African Americans. Reasons for this prominently include increased stress burdens as well as exposure to environmental pollutants. Our lab is very interested in engaging in collaborative, trans-disciplinary research to further investigate such factors.