USF Hyperbaric Biomedical Research Laboratory (HBRL)
Head, Jay B. Dean, PhD
The USF Hyperbaric Biomedical Research Laboratory is a collaborative research facility
housed in the Department of Molecular Pharmacology and Physiology in the laboratories
of Dr. Jay B. Dean: MDL 1027 (813-396-9628) and MDC 4042, 4046 (813-974-8863).
The HBRL maintains several hyperbaric/hypobaric pressure chambers containing
equipment used to measure cellular function in real time via electrophysiology,
polarography, fluorescence microscopy and atomic force microscopy during
experimental perturbations of barometric pressure and gas partial pressures.
The mission of the USF-HBRL is to identify the molecular and cellular mechanisms
involved in the body’s response to artificial atmospheres and altered pressure
environments, including low barometric pressures (hypobaria), normal sea level pressure
(normobaria) and high barometric pressures (hyperbaria). Altered pressure environments
perturb various cellular processes at the molecular level due to the effects of pressure per
se, gas partial pressure alone, and/or the production of secondary reaction productions
such as O2-induced free radicals or CO2-induced protons. Altered pressure environments
are routinely encountered in hyperbaric medicine (hyperbaric oxygen therapy),
underwater diving (hyperbaric gases) and space exploration (hypobaric gases).
To study cellular processes under these conditions, Dr. Dean and his colleagues at USF,
Dr. Enrico Camporesi (Chairman, USF Anesthesiology) and Dr. Dominic D’Agostino
(Molecular Pharmacology and Physiology), have assembled six hyperbaric/hypobaric
pressure chambers for in vitro and in vivo biomedical research. The design, development
and implementation of these novel research tools have been funded primarily through
equipment grants from the Department of Defense and Office of Naval Research (ONR),
Undersea Medicine Program. Ongoing basic research by the USF-HBRL team is
currently supported by the ONR, NIH and USF College of Medicine.
Research capabilities exist over a broad range of working pressures using a variety of
state-of-the art technologies, which include the following:
Room MDL 1027—
 Electrophysiology and real time fluorescence microscopy in in vitro cell and
tissue preparations; 0.3-67.3 atmospheres absolute (ATA)

 Electrophysiology and real time fluorescence microscopy in in vitro cell and
tissue preparations; 1-11 ATA

Dr. J.B. Dean and the 11 ATA
hyperbaric chamber used for making real
time
measurements
of
electrical
signaling and intracellular pH or reactive
oxygen species (via fluorescence
imaging) in living brain tissue slices (rat)
during exposure to hyperbaric oxygen.
Such in vitro experiments are leading to
a better understanding of the early neural
events that precede CNS oxygen toxicity
and, moreover, how hyperbaric oxygen
therapy modulates CNS function.
Top Panel—Looking through the side viewport of the hyperbaric chamber during helium
compression showing a superfused rat hippocampal tissue slice. Two recording microelectrodes and one stimulating electrode are
positioned in the CA1 region of the
hippocampal slice for measuring pre- and
post-synaptic field potentials activated by
electrical stimulation of CA3 axons before,
during and following exposure to hyperbaric
oxygen.
Bottom Panel—Three electrically driven
microdrives are used to position the various
recording probes into the rat brain tissue slice
after the hyperbaric chamber is sealed.
 Atomic force microscopy (AFM) in in vitro cell and tissue preparations; 1-6.8
ATA
3.2 ton hyperbaric chamber houses
an inverted biological fluorescence
microscope (Nikon TE2000) equipped with a top scanning atomic
force microscope (Veeco Bioscope).
Dr. D.P. D’Agostino prepares to scan fixed U87 glioblastoma
cells previously exposed to hyperbaric oxygen. Currently, the
AFM is being modified to operate at hyperbaric pressure,
which we hope to begin before the end of 2007. Once
completed, we will be able to scan living cells during
superfusion with media equilibrated with various test gas
mixtures (O2, CO2, Ar, He, N2) and during compression/
decompression using pure He or N2.
Room MDC 4046—
 Exposure of in vitro tissue slices to hyperbaric gases ranging from 1-6.1 ATA (not
shown)
 Single whole animal (mice, rats) exposures to hyperbaric gases ranging from 13.4 ATA (Sechrist animal chamber, Model 1300)
 Single/multiple whole animal (mice, rats) exposure to hypobaric/hyperbaric gases
ranging from 0.3-7.8 ATA (Reimers Systems, Inc.; see image below, provided by
RSI, Lorton, VA)
Dr. Dean and his colleagues maintain a range of research projects funded by the ONR
and NIH focusing on the O2 and CO2 sensitivities of neurons in the rat brainstem and
hippocampus. In addition, since arriving at USF (July 2006) the researchers have
spearheaded new collaborations with scientists at USF and the United States Navy, the
latter contributing in part to the new National Naval Responsibility in Undersea
Medicine. Ongoing research areas include the following:
 effects of oxidative preconditioning on sensitivity of the CNS to normobaric
hyperoxia and hyperbaric oxygen (HBO2)
 effects of normobaric hyperoxia and HBO2 on production of reactive oxygen/
nitrogen species and ionic currents in cardio-respiratory neurons in brainstem
tissue slices
 electrophysiological effects and interactions between hyperbaric pressure and
narcotic gases on central neurons
 molecular effects of oxidative stress, including graded hyperoxia on the plasma
membrane and cytoskeleton of central neurons as revealed by hyperbaric AFM
 characterization cytoskeletal stiffness and morphological changes in live cultured
renal vascular smooth muscle in response to ligation of integrins with RGD
containing peptide using AFM
For further information about the USF-HBRL please contact Dr. Jay B. Dean at:
Dept. of Molecular Pharmacology and Physiology
School of Basic Biomedical Sciences
College of Medicine
University of South Florida
12901 Bruce B. Downs Blvd., MDC 8
Tampa, Florida 33612-4799
Office phone: 813-974-1547
Laboratories: 813-974-8863, 813-396-9628
Fax: 813-974-3079
jdean@health.usf.edu
Links of interest concerning the USF-HBRL:
 Hyperbaric biomedical research probes new depths of understanding (March 17,
2007): http://hscweb3.hsc.usf.edu/health/now/?p=96
 See 3.2-ton hyperbaric chamber moved! (March 12, 2007):
http://hscvideo2.hsc.usf.edu/asxroot/HSC/Public_Affairs/Hyperbaric.asx
Papers published by Dr. Dean and his colleagues using some of the above mentioned
hyperbaric methodologies to study neural function during exposure to HBO2 and
hyperbaric pressure:
 Dean, J.B., Mulkey, D.K., (2000) Continuous intracellular recording from
mammalian neurons exposed to hyperbaric helium, oxygen, or air, J. Appl.
Physiol., 89:807-822.
http://jap.physiology.org/cgi/reprint/89/2/807?maxtoshow=&HITS=10&hits=10&
RESULTFORMAT=&author1=Dean%2C+Jb&searchid=1&FIRSTINDEX=0&so
rtspec=relevance&resourcetype=HWCIT
 Dean, J.B., Mulkey, D.K., Arehart, J.A. (2000) Details on building a hyperbaric
chamber for intracellular recording in brain tissue slices, J. Appl. Physiol.
(supplemental material) on-line:
http://jap.physiology.org/gci/content/full/89/2/807.
 Mulkey, D.K., Henderson III, R.A., Dean, J.B. (2000) Hyperbaric oxygen
depolarizes solitary complex neurons in tissue slices of rat medulla oblongata.
Adv. Exp. Med. Biol., 475:465-476.
 Mulkey, D.K., Henderson III, R.A., Olson, J.E., Putnam, R.W., Dean, J.B. (2001)
Oxygen measurements in brain stem slices exposed to normobaric hyperoxia and
hyperbaric oxygen. J. Appl. Physiol., 90:1887-1899.
http://jap.physiology.org/cgi/reprint/90/5/1887?maxtoshow=&HITS=10&hits=10
&RESULTFORMAT=&author1=Dean%2C+Jb&searchid=1&FIRSTINDEX=0&
sortspec=relevance&resourcetype=HWCIT
 Mulkey, D.K., Henderson, R.A., Putnam, R.W., and Dean, J.B. (2003) Hyperbaric
oxygen and chemical oxidants stimulate CO2/H+-sensitive neurons in rat brain
stem slices, J. Appl. Physiol., 95 (3): 910-921
http://jap.physiology.org/cgi/reprint/95/3/910?maxtoshow=&HITS=10&hits=10&
RESULTFORMAT=&author1=Dean%2C+Jb&searchid=1&FIRSTINDEX=0&so
rtspec=relevance&resourcetype=HWCIT
 Mulkey, D.K., Henderson, R.A., Putnam, R.W., and Dean, J.B. (2003) Pressure
(<4 ATA) increases membrane conductance and firing rate in the rat solitary
complex, J. Appl. Physiol., 95(3): 922-930
http://jap.physiology.org/cgi/reprint/95/3/922?maxtoshow=&HITS=10&hits=10&
RESULTFORMAT=&author1=Dean%2C+Jb&searchid=1&FIRSTINDEX=0&so
rtspec=relevance&resourcetype=HWCIT
 Dean, J.B., Mulkey, D.K., Garcia, A.J., Putnam, R.W., and Henderson III, R.A.
(2003) Neuronal sensitivity to hyperoxia, hypercapnia, and inert gases at
hyperbaric pressures, J. Appl. Physiol. 95(3): 883-909
http://jap.physiology.org/cgi/reprint/95/3/883?maxtoshow=&HITS=10&hits=10&
RESULTFORMAT=&author1=Dean%2C+Jb&searchid=1&FIRSTINDEX=0&so
rtspec=relevance&resourcetype=HWCIT
 Dean, J.B., Mulkey, D.K., Henderson, R.A., Potter, S.J., and Putnam, R.W.
(2004) Hyperoxia, Reactive O2 Species, and Hyperventilation: O2-Sensitivity of
Brain Stem Neurons, J. Appl. Physiol. 96(2): 784-791
http://jap.physiology.org/cgi/reprint/96/2/784?maxtoshow=&HITS=10&hits=10&
RESULTFORMAT=&author1=Dean%2C+Jb&searchid=1&FIRSTINDEX=0&so
rtspec=relevance&resourcetype=HWCIT
 Mulkey, D.K., Henderson, R.A., Putnam, R.W., Dean, J.B. (2004) Oxidative
stress decreases intracellular pH, Na+/H+ exchange and increases excitability of
solitary complex neurons from rat brain slices, Am. J. Physiol. 286: C940 - 951.
http://ajpcell.physiology.org/cgi/reprint/286/4/C940?maxtoshow=&HITS=10&hit
s=10&RESULTFORMAT=&author1=Dean%2C+JB&searchid=1&FIRSTINDE
X=0&sortspec=relevance&resourcetype=HWCIT
 Mulkey, D.K., Henderson, R.A., Ritucci, N.A., Putnam, R.W., and Dean, J.B.
(2004) Chemical oxidants acidify solitary complex (SC) neurons in rat. Undersea
and Hyperbaric Medicine, 31(1): 107-111
 D’Agostino, D.P., Putnam, R.W., and Dean, J.B. (2007) Superoxide (O2-)
production in CA1 neurons of rat hippocampal slices exposed to graded levels of
oxygen. J. Neurophysiol. (In press: Articles in PresS. J. Neurophysiol [June 6,
2007]. Doi:10.1152/jn.01003.2006;
http://jn.physiology.org/cgi/reprint/01003.2006v1.pdf)
Other relevant links of interest:
 Undersea and Hyperbaric Medical Society (UHMS)
http://www.uhms.org/
 Society for Free Radical Biology and Medicine (SFRBM)
http://www.sfrbm.org/
 Vendors of hyperbaric/ hypobaric pressure animal research chambers
 Reimers Systems, Inc.
http://www.reimerssystems.com/
 OxyHeal
http://www.oxyheal.com/
 Sechrist
http://www.sechristind.com/sechrist-1300.htm