Research Assistant Professor
Dr. Niblock received her B.A. in Psychology, with a concentration in Biology, from the University of Richmond in 1992. She received her Ph.D. in Neuroscience from Wake Forest University in 1998. After a postdoctoral fellowship at Vanderbilt University, Dr. Niblock was a visiting assistant professor of biology at Bowdoin College in Brunswick, ME. In 2002, she was awarded the Deborah Evelyn Barrett Fellowship in SIDS research. She currently is a Parker B. Francis Fellow in Pulmonary Research.
Dr. Niblock is interested in basic brainstem mechanisms possibly associated with sudden infant death syndrome (SIDS). Recent data suggest that some cases of SIDS may be due to abnormalities in serotonergic (5-HT) neurons of the medulla that are critical to state-dependent homeostatic modulation of cardiac and respiratory function. These medullary 5-HT cells and the nuclei they reside in have been shown indirectly to be derived from the rhombic lip, a neural germinal epithelium in the dorsal embryonic hindbrain.
Among these medullary serotonergic cells are chemosensitive neurons with widespread projections to respiratory nuclei. Although the respiratory connections of cells in these nuclei are well described, it is unknown if or how the 5-HT cells communicate with each other and what factors may be relevant to connections and functions among 5-HT cells (i.e. embryonic origin, final location within the brainstem, neurochemical phenotype). Connections among medullary 5-HT cells that reside in different locations in the brainstem may form a neural network, a system of cells capable of integrating a variety of inputs that share a final common pathway for modulation of autonomic control.
Dr. Niblock's experiments use in vivo and in vitro anatomical as well as in vitro electrophysiological approaches in a transgenic mouse model that allows the subset of serotonergic cells derived from the rhombic lip to be visualized using fluorescence microscopy. These experiments address 2 fundamental issues: (1) do 5-HT cells derived from the rhombic lip communicate with each other or other 5-HT cells in the brainstem, forming a neural network? and (2) do rhombic lip-derived 5-HT cells share a common function?
Knowledge of the connectivity and function among these cells is fundamental to our understanding of the neurobiological control of respiration and its disorders, especially SIDS, as well as our understanding of neural networks comprised of cells that traditionally have been classified in distinct nuclei.
Niblock MM, Brunso-Bechtold JK, Henkel CK. Fiber outgrowth and pathfinding in the developing auditory brainstem. Brain Res Dev Brain Res 1995 Apr 18;85(2):288-92.
Niblock MM, Brunso-Bechtold JK, Lynch CD, Ingram RL, McShane T, Sonntag WE.Distribution and levels of insulin-like growth factor I mRNA across the life span in the Brown Norway x Fischer 344 rat brain. Brain Res 1998 Aug 31;804(1):79-86.
Niblock MM, Brunso-Bechtold JK, Riddle DR.Insulin-like growth factor I stimulates dendritic growth in primary somatosensory cortex. J Neurosci 2000 Jun 1;20(11):4165-76.
Florence SL, Boydston LA, Hackett TA, Lachoff HT, Strata F, Niblock MM. Sensory enrichment after peripheral nerve injury restores cortical, not thalamic, receptive field organization. Eur J Neurosci 2001 May;13(9):1755-66.
Niblock MM, Brunso-Bechtold JK, Riddle DR. Laminar variation in neuronal viability and trophic dependence in neocortical slices. J Neurosci Res 2001 Sep 1;65(5):455-62.