Maria A. Serrat, Ph.D.

Maria Serrat, Ph.D.Assistant Professor
Department: Anatomy and Pathology
Research Cluster: Neuroscience and Developmental Biology
Offices: BBSC 301L, MEB 207 | Laboratory: MEB 206
Phone: (304) 696-7392
E-mail: serrat@marshall.edu

Research Interests

Ambient temperature and physical activity have a surprising impact on bone length, but it is unclear how such common variables regulate growth of the postnatal skeleton. We study environmental inputs on bone elongation in growth plates, the regions of cartilage where bone lengthening occurs. Our long-term goal is to identify the physiological mechanisms underlying temperature- and exercise- enhanced bone elongation in the growth plate, with the intent of finding new ways to potentially treat growth impediments in children. We employ whole animal and bone culture models to test specific hypotheses about environmental effects on the growth plate matrix, its vasculature, and nutrient supply. We use a variety of tools such as live animal imaging; histology and immunostaining; fluorochrome bone labeling; micro-CT analysis; and fluorescent microsphere blood flow assays. Our research is important for an evolutionary understanding of limb length variation among mammals in different environments and may aid in developing more effective treatments for childhood growth disorders.

Laboratory Projects

Imaging skeletal growth plates using in vivo multiphoton microscopy

Multiphoton microscopy is an emerging technology for live animal imaging that offers exciting possibilities for the study of growth plate dynamics in vivo. We have worked for the past year with collaborators at Cornell University to establish a platform for imaging intact skeletal growth plates. We are now using this method to assess how systemic regulators arrive at and move within the cartilage matrix of the growth plate under various experimental conditions. This system provides a new mechanism for understanding the physiological regulation of bone growth through the ability to dynamically measure changes in solute delivery to the growth plate of a living animal.

Serrat Fig (1)

Thermal Image of Mice during a Limb Heating Experiment (Serrat Lab) Limb heating experiments are being conducted in the Serrat Lab to study mechanisms underlying heat-enhanced bone elongation. Thermal image of juvenile mice on a heating pad (left) shows the temperature differential between heat-treated and non-treated sides. Limbs are equilibrated to 40C during the daily treatments. Digital image (right) shows foam separators that are used to keep the non-treated side at a cooler 30C. Images captured June 2014 by Ph.D. student Holly Tamski and Maria Serrat, Ph.D.

Determining how temperature alters cartilage growth in vitro

The objective of this study is to determine how temperature modulates bone elongation using an established bone culture model. We grow intact metatarsal bones from neonatal mice in vitro to isolate local effects of temperature on the growth plate, since this system is largely free of systemic inputs. Analysis by multiphoton microscopy enables visualization of intact growth plate cartilage, which can be manipulated and assessed in real time. Cell morphology and protein expression are evaluated using standard histology and immunohistochemistry on fixed preps and whole mount samples.

Selected Publications

Environmental temperature impact on bone and cartilage growth.
Serrat MA. Compr Physiol. 2014 Apr;4(2):621-55. doi: 10.1002/cphy.c130023.
PMID: 24715562 [PubMed - in process]

Hindlimb heating increases vascular access of large molecules to murine tibial growth plates measured by in vivo multiphoton imaging.
Serrat MA, Efaw ML, Williams RM. J Appl Physiol (1985). 2014 Feb 15;116(4):425-38. doi: 10.1152/japplphysiol.01212.2013. Epub 2013 Dec 26. PMID: 24371019 [PubMed - in process]

Allen’s rule revisited: temperature influences bone elongation during a critical period of postnatal development.
Serrat MA. Anat Rec (Hoboken). 2013 Oct;296(10):1534-45. doi: 10.1002/ar.22763. Epub 2013 Aug 19. PMID: 23956063 [PubMed - indexed for MEDLINE]

Exercise mitigates the stunting effect of cold temperature on limb elongation in mice by increasing solute delivery to the growth plate.
Serrat MA, Williams RM, Farnum CE. J Appl Physiol (1985). 2010 Dec;109(6):1869-79. doi: 10.1152/japplphysiol.01022.2010. Epub 2010 Oct 7. PMID: 20930127 [PubMed - indexed for MEDLINE] Free PMC Article This paper used in vivo multiphoton microscopy to image growth plate cartilage with collaborators at Cornell University.

Serrat MA. Measuring bone blood supply in mice using fluorescent microspheres. Nature Protocols. 4(12): 1749-58. 2009. Single-author paper utilizing techniques developed by Dr. Serrat while she was a student at Kent State University.

Laboratory Personnel

Gabriela Ion, Ph.D. – Research Instructor, Department of Anatomy and Pathology
Holly Tamski – Biomedical Sciences Ph.D. student