Matthew R. Hodges , Ph.D.
Phone: (414) 955-7528
B.A. Biology, Carleton College, 1998
Ph.D. Physiology, Medical College of Wisconsin, 2004
Parker B. Francis Fellow, Yale University School of Medicine, 2006-2009
CENTRAL CHEMORECEPTION AND THE RESPIRATORY NETWORK
Every cell in the body requires a continuous supply of oxygen and constant removal of carbon dioxide, and as a result we breathe continuously from birth to death to ensure adequate gas exchange. A decrease in the blood oxygen levels or an increase in carbon dioxide (which decreases pH) both act to increase ventilation in classic feedback fashion. However, it remains unknown which neurons within the brainstem serve as detectors of brain carbon dioxide levels and/or pH, and how these neurons send this information to the neuronal network that generate respiratory rhythm and muscle activation patterns.
Our goal in the Hodges laboratory is to use a variety of techniques, from genetic manipulation to recordings from single neurons in vitro, and studying intact animals to determine which neurons serve as chemoreceptors for breathing, how they detect changes in carbon dioxide and/or pH, and how a change in their activity translates to a change in ventilation. The techniques we use in our laboratory include patch-clamp recording (from primary cell culture and acute brainstem slices), en bloc whole nerve recordings from isolated brainstem preparations, flow-through plethysmography (to measure ventilation rats and mice), in vivo microdialysis (to generate focal brain acidosis and measure levels of neurotransmitters), and peripheral chemoreceptor (carotid body) denervation.
M.R. Hodges, S. Best, G.B. Richerson. Altered ventilatory and thermoregulatory control in male and female adult Pet-1 null mice. Respir. Physiol. Neurobiol. 177(2): 133-40, 2011.
J.M. Bonis, S.E. Neumueller, B.D. Marshall, K.L. Krause, B. Qian, L.G. Pan, M.R. Hodges, H.V. Forster. The effects of lesions in the dorsolateral pons on the coordination of swallowing and breathing in awake goats. Respir. Physiol. Neurobiol. 175(2):272:82, 2011.
S. Neumueller, M.R. Hodges, K. Krause, B. Marshall, J. Bonis, B. Qian, L.G. Pan, H.V. Forster. Anatomic changes in multiple brainstem nuclei after incremental, near-complete neurotoxic destruction of the pre-Bötzinger Complex in adult goats. Respir. Physiol. Neurobiol. (175(1): 1-11, 2011).
D. Riley, M. Dwinell, B. Qian, K.L. Krause, J.M. Bonis, S. Neumueller, B.D. Marshall, M.R. Hodges, H.V. Forster. Differences between three different rat strains in the number of K+ channel-immunoreactive neurons in the medullary raphé nucleus. J. Appl. Physiol. 108(4): 1003-10, 2010.
M.R. Hodges, M. Wehner, J. Aungst, J.C. Smith, G.B. Richerson. Transgenic mice lacking serotonin neurons have severe apnea and high mortality during development. J. Neurosci. 29(33): 10341-9, 2009.
M.R. Hodges, G.B. Richerson. Interaction between defects in ventilatory and thermoregulatory control in mice lacking 5-HT neurons. Respir. Physiol. Neurobiol. 164(3): 350-357, 2008.
M.R. Hodges, G.B. Richerson. Contributions of 5-HT neurons to respiratory control: neuromodulatory and trophic effects. Respir. Physiol. Neurobiol. 164: 222-232, 2008.
M.R. Hodges, G.J. Tattersall, M.B. Harris, S.D. McEvoy, D.N. Richerson, E.S. Deneris, R.L. Johnson, Z.F. Chen, G.B. Richerson. Defects in breathing and thermoregulation in mice with near-complete absence of serotonin neurons. J. Neurosci., 28(10): 2495-505, 2008.
Pathway to Independence Award (NIH R00 HL097033-03), 09-01-09 – 07-31-14
PI: M.R. Hodges
Cutting-edge Basic Research Award (NIDA R21 DA031561-01), 7/1/11-6/30/13
PI: A. Geurts and M.R. Hodges
VA Merit Review 2885-02P, H.V. Forster (PI), 04/01/10- 03-31-14
Veteran’s Affairs Administration
Co-I: M.R. Hodges (PI: Forster)
Parker B. Francis Postdoctoral Award in Pulmonary Research (07/01/2006 – 07/01/2009): “Development of CO2 Sensitivity among Different Populations of Medullary Serotonergic Neurons.”