Dr. Missy Niblock
I am a neurobiologist studying the neuronal circuits in the brain
that regulate breathing to maintain normal concentrations of
oxygen and carbon dioxide in the blood. I am especially interested
in the brainstem cells that are able to sense and respond to
changes in blood levels of carbon dioxide. In my laboratory
we study the anatomy of these important cells - see more on
my research below.
Cell Biology (Bio 313)
Developmental Neurobiology (Bio 327)
This Is Your Life (Bio 127)
Writing Science News (Sci 259)
Postdoctoral Research 2003-2007
Eugene Nattie, M.D., Dartmouth Medical School, Physiology Department
The anatomy and development of chemosensitive cells in the mouse brainstem
Postdoctoral Research 2002-2003
Hannah Kinney, M.D., Harvard University Medical School, Children's
Hospital, and Dartmouth Medical School
The role of the developing ventral medullary serotonergic network in
Sudden Infant Death Syndrome
Postdoctoral Research 1998-2000
Sherre Florence, Ph.D., Vanderbilt University
Somatosensory cortical plasticity following perinatal nerve injury
or amputation in macaque monkeys
Graduate Student Research 1992-1998
Judy Brunso-Bechtold, Ph.D., and David Riddle, Ph.D., Wake Forest University
Insulin-like growth factor 1 during development and aging
B.A. Psychology with concentration in Biology, 1992
University of Richmond, VA
Undergraduate Student Research 1991-1992 , Craig Kinsley, Ph.D.
Effects of pregnancy on plasticity in the rat cerebral cortex
Undergraduate Student Research 1990-1991, JoAnn Preston, Ph.D.
Meta-analysis of publication biases towards positive results
The mouse brain is smaller than a dime, but in many ways it is very similar to the human brain. This fluorescent photomicrograph shows activated neurons (bright red) in a cross-section of the brainstem from an FTL mouse that was exposed to 5% carbon dioxide. The section was stained with antibodies against the beta-galctosidase reporter protein (the protein product of the lacZ gene).
laboratory, we use neuroanatomical approaches to study chemosensitive cells in
the mouse brainstem and cerebellum. These specialized neurons, called central
chemoreceptors, are able to sense changes in blood levels of carbon
dioxide and respond to those changes by increasing breathing.
addition to being interesting from a basic science perspective, knowledge of
central chemoreceptor neuroanatomy is clinically relevant. A defect in central
chemoreception is hypothesized to be one of the underlying causes of the sudden
infant death syndrome (SIDS). SIDS is the leading cause of postneonatal infant
mortality in the United States, with an overall incidence of 0.6/1000 live births.
One current working model in SIDS research is that SIDS infants have a defect
in central chemoreception that renders them unable to increase their breathing
when their blood carbon dioxide levels rise. A rise in blood carbon dioxide can
be caused by something as simple as a blanket over the face, or by sleeping in
a facedown position, so that expired carbon dioxide is re-breathed by an
mouse model we are using in the laboratory is the Fos-Tau-lacZ (FTL)
mouse. This unique mouse harbors a tau-lacZ transgene under the
control of the c-fos promoter. Under conditions that elicit the expression of c-fos,
such as increased blood carbon dioxide levels, the lacZ reporter gene
is turned on, and, due to fusion of the lacZ reporter protein
(beta-galactosidase) to the microtubule-associated protein Tau, the reporter
protein is transported to neuronal cell processes (axons and dendrites) in
addition to being present in the cell bodies. The presence of
beta-galactosidase in the axons and dendrites allows us to study the morphology
and map the connections of cells that respond to carbon dioxide.
Immunohistochemical and in situ hybridization experiments in these mice
following activation of c-fos and trangene expression provide
information about the neuronal connections and phenotype(s) of the cells
involved in the response to carbon dioxide. Data from these mice will give us
insight into the cells, nuclei, and pathways that govern the respiratory
response to increased carbon dioxide levels. Ultimately, we hope these data
contribute to our understanding of SIDS. My future studies will include further
characterization of carbon dioxide-sensitive cells, such as determining which
ion channels, membrane bound transporters, and neuropeptides these important
Selected Publications (* indicates student co-author)
Xia L., Damon T., Niblock M.M., Bartlett Jr D., Leiter J.C. 2007. Unilateral
microdialysis of gabazine in the dorsal medulla reverses thermal prolongation
of the laryngeal chemoreflex in decerebrate piglets. Journal of Applied
Physiology. In press.
Penatti E.M., Berniker A.V., Kereshi B., Cafaro C., Kelly M.L., Niblock,
M.M., Gao H.G., Kinney H.C., Li A., Nattie E.E. 2006. Ventilatory response
to hypercapnia and hypoxia after extensive lesion of medullary serotonergic
neurons in newborn conscious piglets. Journal of Applied Physiology 101:
Darnall R.A., Harris M.B., Gill W.H., Hoffman J.M., Brown J.W., Niblock
M.M. 2005. Inhibition of serotonergic neurons in the nucleus paragigantocellularis
lateralis fragments sleep and decreases rapid eye movement sleep in the
piglet: implications for sudden infant death syndrome. Journal of Neuroscience
Luce C.J., Belliveau R.A., Paterson D.S., Kelly M.L., Sleeper L.A.,
Filiano J.J., Kinney H.C. 2005. Comparative anatomical assessment of
the piglet as a model for the developing human medullary serotonergic
system. Brain Research, Brain Research Reviews 50:169-83.
Niblock, M.M., Kinney, H.C., Luce, C.J., Belliveau, R.A., and Filiano,
J.J. 2004. The development of the medullary serotonergic system in the
piglet. Autonomic Neuroscience: Basic and Clinical 110: 65-80.
Florence, S.L., Boydston, L.A., Hackett, T.A., Lachoff, H. Taub,
Strata, F., and Niblock, M.M. 2001. Sensory enrichment promotes cortical,
not thalamic, refinement of disorder produced by peripheral nerve injury.
European Journal of Neuroscience 13: 1755-1766.
Niblock, M.M., Brunso-Bechtold, J.K., and Riddle, D.R. 2001. Laminar
differences in neuronal viability in a slice preparation. Journal of Neuroscience
Niblock, M.M., Brunso-Bechtold, J.K., and Riddle, D.R. 2000. Insulin-like
growth factor I increases dendritic growth in primary sensory cortex. Journal
of Neuroscience 20: 4165-4176.
Niblock, M.M., Brunso-Bechtold, J.K., Lynch, C.D., Ingram, R.L.,
McShane, T., and Sonntag, W.E. 1998. Distribution and levels of insulin-like
growth factor I across the life span in the Brown-Norway X Fischer 344
rat brain. Brain Research 804: 79-86.
Brunso-Bechtold, J.K., and Henkel, C.K. 1995. Fiber outgrowth and
pathfinding in the developing auditory brainstem. Developmental Brain
Research 85: 288-292.
Selected Presentations (* indicates student co-author)
Penatti, E.M., Kereshi, B., Li, A., Gao, H.G., Niblock, M.M., and Nattie,
E.E. 2005 Ventilatory response to hypercapnia in newborn piglets and the
role of serotonergic neurons. Society for Neuroscience Abstracts 31.
Hoffman, J.M., Harris, M.B., Gill, W.H., Niblock, M.M., and Darnall,
R.A. 2004. Inhibition of serotonergic neurons in the caudal medulla of
conscious, awake and sleeping piglets alters the respiratory response to
hypoxia. Society for Neuroscience Abstracts 30.
Darnall, R.A., Harris, M.B. , Gill, W.H., Niblock, M.M. 2003. Destruction
of serotonergic neurons in the paragignatocellularis lateralis (PGCL),
a component of the rostral ventral medulla (RVM), disrupts sleep architechture
in piglets. Society for Neuroscience Abstracts 29.
Niblock, M.M., Kinney,
H.C., and Dymecki, S.M. 2003. A Subset of Medullary Serotonergic Neurons
Arises from Dorsal Rhombencephalon Corresponding to the Rhombic Lip. Society
for Neuroscience Abstracts 29.
Niblock, M.M., Filiano, J.J., Messier, M.L., Paterson, D.S., Luce,
C.J., Belliveau, R.A., Gao, H., and Kinney, H.C. 2002. Comparative anatomy
of the brainstem serotonergic system between the piglet and human infant.
Society for Neuroscience Abstracts 28.
Niblock, M.M. and Florence, S.L. 2000. Growth of new connections
from the face representation into hand cortex after forelimb amputation.
Society for Neuroscience Abstracts 26.
Riddle, D.R., Niblock, M.M., and Brunso-Bechtold, J.K. 1999. IGF-I
increases dendritic growth in primary sensory cortex. Society for Neuroscience
Abstracts 25: 766.
Niblock, M.M., Riddle, D.R., and Brunso-Bechtold, J.K. 1997. Laminar
variation in neuronal viability in a slice preparation of neonatal rat
brain. Society for Neuroscience Abstracts 23: 902.
Brunso-Bechtold, J.K., Lynch, C.D., McShane, T.M., Cooney, P.T.,
Niblock, M.M., Hutchins, P.M., and Sonntag, W.E. 1996. Insulin-like growth
factor I (IGF-I) gene expression in brain vasculature: influence of age.
Society for Neuroscience Abstracts 22: 1236.
Niblock, M.M., Lynch, C.D., Cooney, P.T., McShane, T., Brunso-Bechtold,
J.K., and Sonntag, W.E. 1996. Neuronal IGF-I mRNA expression during development
and aging in Fischer 344 X Brown-Norway Rats. Society for Neuroscience
Abstracts 22: 1236.
Niblock, M.M., Brunso-Bechtold, J.K., and Henkel, C.K. 1994. Fiber
outgrowth and pathfinding in the developing auditory brainstem. Society
for Neuroscience Abstracts 20: 1107.
Selected Funding Awarded
2003-2006. Parker B. Francis Fellowship in Pulmonary Research, Dartmouth
Deborah Evelyn Barrett Fellowship in SIDS Research, Harvard Medical
School and Dartmouth Medical School.
2000-2001. Bowdoin College Faculty Fund Research Grant Award, Bowdoin College.
1992-1998. Graduate Fellowship in Neuroscience, Wake Forest University.
1991-1992. Institutional Student Research Grant Award, University of Richmond.