Igor Kraev

Dr. Igor Kraev

School of Life, Health and Chemical Sciences, STEM, Open University
+1
orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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1 January 2005 in Neuroscience
Verified
Journal Article
Closed access
MSM.G. Stewart
M.G. Stewart
HDH.A. Davies
H.A. Davies
CSC. Sandi
C. Sandi
IKIgor Kraev
Igor Kraev
VRVadim Rogachevsky
Vadim Rogachevsky
VPV.I. Popov
V.I. Popov

21 September 2011 in Journal of Neuroscience
Verified
Journal Article
Open access
PDF file
XWXiao-Dong Wang
Xiao-Dong Wang
GRGerhard Rammes
Gerhard Rammes
IKIgor Kraev
Igor Kraev
MWMiriam Wolf
Miriam Wolf
CLClaudia Liebl
Claudia Liebl
MSMathias Schmidt
Mathias Schmidt
Childhood traumatic events hamper the development of the hippocampus and impair declarative memory in susceptible individuals. Persistent elevations of hippocampal corticotropin-releasing factor (CRF), acting through CRF receptor 1 (CRF1), in experimental models of early-life stress have suggested a role for this endogenous stress hormone in the resulting structural modifications and cognitive dysfunction. However, direct testing of this possibility has been difficult. In the current study, we subjected conditional forebrain CRF1knock-out (CRF1-CKO) mice to an impoverished postnatal environment and examined the role of forebrain CRF1in the long-lasting effects of early-life stress on learning and memory. Early-life stress impaired spatial learning and memory in wild-type mice, and postnatal forebrain CRF overexpression reproduced these deleterious effects. Cognitive deficits in stressed wild-type mice were associated with disrupted long-term potentiation (LTP) and a reduced number of dendritic spines in area CA3 but not in CA1. Forebrain CRF1deficiency restored cognitive function, LTP and spine density in area CA3, and augmented CA1 LTP and spine density in stressed mice. In addition, early-life stress differentially regulated the amount of hippocampal excitatory and inhibitory synapses in wild-type and CRF1-CKO mice, accompanied by alterations in the neurexin-neuroligin complex. These data suggest that the functional, structural and molecular changes evoked by early-life stress are at least partly dependent on persistent forebrain CRF1signaling, providing a molecular target for the prevention of cognitive deficits in adults with a history of early-life adversity.

19 October 2014 in Philosophical Transactions of the Royal Society B: Biological Sciences
Verified
Journal Article
Open access
NMNikolai Medvedev
Nikolai Medvedev
VPVictor Popov
Victor Popov
CHChristian Henneberger
Christian Henneberger
IKIgor Kraev
Igor Kraev
Dmitri A RusakovDmitri A Rusakov
Dmitri A Rusakov
MSMichael G. Stewart
Michael G. Stewart
This paper examines the relationship between the morphological modality of 189 dendritic spines and the surrounding astroglia using full three-dimensional reconstructions of neuropil fragments. An integrative measure of three-dimensional glial coverage confirms that thin spine postsynaptic densities are more tightly surrounded by glia. This distinction suggests that diffusion-dependent synapse–glia communication near ‘learning’ synapses (associated with thin spines) could be stronger than that near ‘memory’ synapses (associated with larger spines).

3 September 2018 in Nature Communications
Verified
Journal Article
Open access
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Dmitri A RusakovDmitri A Rusakov
Dmitri A Rusakov
LBLucie Bard
Lucie Bard
TJThomas P. Jensen
Thomas P. Jensen
JRJames P. Reynolds
James P. Reynolds
IKIgor Kraev
Igor Kraev
Dmitri A RusakovDmitri A Rusakov
Dmitri A Rusakov
Electrically non-excitable astroglia take up neurotransmitters, buffer extracellular K+and generate Ca2+signals that release molecular regulators of neural circuitry. The underlying machinery remains enigmatic, mainly because the sponge-like astrocyte morphology has been difficult to access experimentally or explore theoretically. Here, we systematically incorporate multi-scale, tri-dimensional astroglial architecture into a realistic multi-compartmental cell model, which we constrain by empirical tests and integrate into the NEURON computational biophysical environment. This approach is implemented as a flexible astrocyte-model builder ASTRO. As a proof-of-concept, we explore an in silico astrocyte to evaluate basic cell physiology features inaccessible experimentally. Our simulations suggest that currents generated by glutamate transporters or K+channels have negligible distant effects on membrane voltage and that individual astrocytes can successfully handle extracellular K+hotspots. We show how intracellular Ca2+buffers affect Ca2+waves and why the classical Ca2+sparks-and-puffs mechanism is theoretically compatible with common readouts of astroglial Ca2+imaging.

10 September 2019 in Frontiers in Cellular and Infection Microbiology
Verified
Journal Article
Open access
PDF file
UKUchini S. Kosgodage
Uchini S. Kosgodage
PMPaul Matewele
Paul Matewele
BABrigitte Awamaria
Brigitte Awamaria
IKIgor Kraev
Igor Kraev
PWPurva Warde
Purva Warde
Sigrun LangeSigrun Lange
Sigrun Lange
Membrane vesicles (MVs) released from bacteria participate in cell communication and host-pathogen interactions. Roles for MVs in antibiotic resistance are gaining increased attention and in this study we investigated if known anti-bacterial effects of cannabidiol (CBD), a phytocannabinoid from Cannabis sativa, could be in part attributed to effects on bacterial MV profile and MV release. We found that CBD is a strong inhibitor of MV release from Gram-negative bacteria (E. coli VCS257), while inhibitory effect on MV release from Gram-positive bacteria (S. aureus subsp. aureus Rosenbach) was negligible. When used in combination with selected antibiotics, CBD significantly increased the bactericidal action of several antibiotics in the Gram-negative bacteria. In addition, CBD increased antibiotic effects of kanamycin in the Gram-positive bacteria, without affecting MV release. CBD furthermore changed protein profiles of MVs released from E. coli after 1 h CBD treatment. Our findings indicate that CBD may pose as a putative adjuvant agent for tailored co-application with selected antibiotics, depending on bacterial species, to increase antibiotic activity, including via MV inhibition, and help reduce antibiotic resistance.

1 June 2005 in European Journal of Neuroscience
Verified
Journal Article
Closed access
PDF file
MSM. G. Stewart
M. G. Stewart
NMN. I. Medvedev
N. I. Medvedev
VPV. I. Popov
V. I. Popov
RSR. Schoepfer
R. Schoepfer
HDH. A. Davies
H. A. Davies
JRJ. J. Rodríguez
J. J. Rodríguez