Hubert H. Kerschbaum

Prof. Dr. Hubert H. Kerschbaum

Department of Cell Biology, University of Salzburg, 5020 Salzburg, Austria

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2014 in Neurobiology of Learning and Memory
Verified
Journal Article
Open access
MWMelanie Wegerer
Melanie Wegerer
HKHubert H. Kerschbaum
Hubert H. Kerschbaum
JBJens Blechert
Jens Blechert
FWFrank H. Wilhelm
Frank H. Wilhelm
Posttraumatic stress disorder (PTSD) can be conceptualized as a disorder of emotional memory showing strong (conditioned) responses to trauma reminders and intrusive memories among other symptoms. Women are at greater risk of developing PTSD than men. Recent studies have demonstrated an influence of ovarian steroid hormones in both fear conditioning and intrusive memory paradigms. However, although intrusive memories are considered non-extinguished emotional reactions to trauma reminders, none of the previous studies has investigated effects of ovarian hormones on fear conditioning mechanisms and intrusive memories in conjunction. This may have contributed to an overall inconsistent picture of the role of these hormones in emotional learning and memory. To remedy this, we exposed 37 healthy women with a natural menstrual cycle (during early follicular or luteal cycle phase) to a novel conditioned-intrusion paradigm designed to model real-life traumatic experiences. The paradigm included a differential fear conditioning procedure with short violent film clips as unconditioned stimuli. Intrusive memories about the film clips were assessed ambulatorily on subsequent days. Women with lower levels of estradiol displayed elevated differential conditioned skin conductance responding during fear extinction and showed stronger intrusive memories. The inverse relationship between estradiol and intrusive memories was at least partially accounted for by the conditioned responding observed during fear extinction. Progesterone levels were not associated with either fear acquisition/extinction or with intrusive memories. This suggests that lower levels of estradiol might promote stronger symptoms of PTSD through associative processes.

1 August 2014 in Brain Research
Verified
Journal Article
Open access
CBChristina P. Brötzner
Christina P. Brötzner
WKWolfgang Klimesch
Wolfgang Klimesch
MDMichael Doppelmayr
Michael Doppelmayr
AZAndrea Zauner
Andrea Zauner
HKHubert H. Kerschbaum
Hubert H. Kerschbaum
Ongoing intrinsic brain activity in resting, but awake humans is dominated by alpha oscillations. In human, individual alpha frequency (IAF) is associated with cognitive performance. Noticeable, performance in cognitive and emotional tasks in women is associated with menstrual cycle phase and sex hormone levels, respectively. In the present study, we correlated frequency of alpha oscillation in resting women with menstrual cycle phase, sex hormone level, or use of oral contraceptives. Electroencephalogram (EEG) was recorded from 57 women (aged 24.07 ± 3.67 years) having a natural menstrual cycle as well as from 57 women (aged 22.37 ± 2.20 years) using oral contraceptives while they sat in an armchair with eyes closed. Alpha frequency was related to the menstrual cycle phase. Luteal women showed highest and late follicular women showed lowest IAF or center frequency. Furthermore, IAF as well as center frequency correlated negatively with endogenous estradiol level, but did not reveal an association with endogenous progesterone. Women using oral contraceptives showed an alpha frequency similar to women in the early follicular phase. We suggest that endogenous estradiol modulate resting alpha frequency.

23 June 2021 in Frontiers in Cell and Developmental Biology
Verified
Journal Article
Open access
PDF file
Markus RitterMarkus Ritter
Markus Ritter
NBNikolaus Bresgen
Nikolaus Bresgen
HKHubert H. Kerschbaum
Hubert H. Kerschbaum
The volumes of a cell [cell volume (CV)] and its organelles are adjusted by osmoregulatory processes. During pinocytosis, extracellular fluid volume equivalent to its CV is incorporated within an hour and membrane area equivalent to the cell’s surface within 30 min. Since neither fluid uptake nor membrane consumption leads to swelling or shrinkage, cells must be equipped with potent volume regulatory mechanisms. Normally, cells respond to outwardly or inwardly directed osmotic gradients by a volume decrease and increase, respectively, i.e., they shrink or swell but then try to recover their CV. However, when a cell death (CD) pathway is triggered, CV persistently decreases in isotonic conditions in apoptosis and it increases in necrosis. One type of CD associated with cell swelling is due to a dysfunctional pinocytosis. Methuosis, a non-apoptotic CD phenotype, occurs when cells accumulate too much fluid by macropinocytosis. In contrast to functional pinocytosis, in methuosis, macropinosomes neither recycle nor fuse with lysosomes but with each other to form giant vacuoles, which finally cause rupture of the plasma membrane (PM). Understanding methuosis longs for the understanding of the ionic mechanisms of cell volume regulation (CVR) and vesicular volume regulation (VVR). In nascent macropinosomes, ion channels and transporters are derived from the PM. Along trafficking from the PM to the perinuclear area, the equipment of channels and transporters of the vesicle membrane changes by retrieval, addition, and recycling from and back to the PM, causing profound changes in vesicular ion concentrations, acidification, and—most importantly—shrinkage of the macropinosome, which is indispensable for its proper targeting and cargo processing. In this review, we discuss ion and water transport mechanisms with respect to CVR and VVR and with special emphasis on pinocytosis and methuosis. We describe various aspects of the complex mutual interplay between extracellular and intracellular ions and ion gradients, the PM and vesicular membrane, phosphoinositides, monomeric G proteins and their targets, as well as the submembranous cytoskeleton. Our aim is to highlight important cellular mechanisms, components, and processes that may lead to methuotic CD upon their derangement.

1 September 2016 in Brain Connectivity
Verified
Journal Article
Closed access
BPBelinda Pletzer
Belinda Pletzer
JCJulia Sophia Crone
Julia Sophia Crone
MKMartin Kronbichler
Martin Kronbichler
HKHubert H. Kerschbaum
Hubert H. Kerschbaum
Menstrual cycle dependent changes have been reported for a variety of functions, including cognition, attention, emotion, inhibition and perception. For several of these functions an effect of hormonal contraceptives has also been discussed. Cognitive, attentional, emotional, inhibitory and perceptual functions have been linked to distinct intrinsic connectivity networks during the resting state. However, changes in resting state connectivity across the menstrual cycle phase and due to hormonal contraceptive use have only been investigated in two selected networks and without controlling for the type of hormonal contraceptives. In the present study, we demonstrate menstrual cycle and hormonal contraceptive-dependent changes in several intrinsic connectivity networks, including networks that have been related to emotion processing, olfaction, audition, vision, coordination and two lateralized fronto-parietal networks related to a variety of cognitive functions. These changes parallel behavioral changes in the functions associated with these networks. Changes in connectivity and changes in behavior occur during the same cycle phases. Furthermore, hormonal contraceptive dependent effects were observed in the same networks and same target sites as menstrual cycle related changes and were dependent on the androgenicity of the progestin component contained in the hormonal contraceptive.

30 August 2011 in Apoptosis
Verified
Journal Article
Closed access
PDF file
BKBarbara Klein
Barbara Klein
KWKatrin Wörndl
Katrin Wörndl
ULUrsula Lütz-Meindl
Ursula Lütz-Meindl
HKHubert H. Kerschbaum
Hubert H. Kerschbaum

20 January 2014 in Leukemia
Verified
Journal Article
Open access
EGE M Grössinger
E M Grössinger
LWL Weiss
L Weiss
SZSusanna Zierler
Susanna Zierler
SRS Rebhandl
S Rebhandl
Peter KrennPeter Krenn
Peter Krenn
HKHubert H. Kerschbaum
Hubert H. Kerschbaum
Leukemia is one of the leading journals in hematology and oncology. It is published monthly and covers all aspects of the research and treatment of leukemia and allied diseases. Studies of normal hemopoiesis are covered because of their comparative relevance.