Richard Simerly

Professor
Pediatrics, Keck School of Medicine
Neurobiology, Biological Sciences
Director, Saban Neuroscience Program

Research Topics

  • Axon targeting in limbic and hypothalamic neural pathways
  • Leptin receptor signaling in developing hypothalamic circuitry
  • Development of sexually dimorphic forebrain regions

Research Images

Research Overview

The development of the brain depends on complex interactions between genetic factors and environmental influences, such as neuronal activity, growth factors and circulating hormones. Hormones secreted by peripheral organs can determine the number and chemical phenotype of specific sets of neurons during development, as well as direct formation of connections with other parts of the brain. Currently, we are studying the organization and development of forebrain pathways that regulate feeding and energy homeostasis. Recent findings indicate that these neural pathways develop under the influence of the adipocyte derived hormone leptin during discrete temporal domains, suggesting that there are region-specific, hormonally directed mechanisms governing the assembly of homeostatic circuits. Using axonal labeling methods and both in vitro and in vivo experimental approaches, we are determining if manipulations of genes known to participate in leptin signaling in mature animals also influence the development of the pathways that mediate hypothalamic responses to changes in energy balance. The results of this work indicate that leptin is indeed a major developmental factor that may mediate the developmental effects of a variety of environmental factors including nutrition.