TY - JOUR AU - Kovács, Krisztián TI - Relevance of a novel circuit‐level model of episodic memories to alzheimer’s disease JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 23 PY - 2022 IS - 1 PG - 13 SN - 1661-6596 DO - 10.3390/ijms23010462 UR - https://m2.mtmt.hu/api/publication/32587927 ID - 32587927 N1 - Export Date: 12 January 2022 Correspondence Address: Kovács, K.A.; Retina Research Laboratory, Tűzoltó U. 37‐47, Hungary; email: kovacs.krisztian@med.se LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Krisztián TI - Episodic Memories: How do the Hippocampus and the Entorhinal Ring Attractors Cooperate to Create Them? JF - FRONTIERS IN SYSTEMS NEUROSCIENCE J2 - FRONT SYST NEUROSCI VL - 14 PY - 2020 PG - 16 SN - 1662-5137 DO - 10.3389/fnsys.2020.559186 UR - https://m2.mtmt.hu/api/publication/31607663 ID - 31607663 N1 - Cited By :1 Export Date: 21 October 2022 Correspondence Address: Kovács, K.A.; Retina Research Laboratory, Hungary; email: kkovacs.ist@t-online.hu AB - The brain is capable of registering a constellation of events, encountered only once, as an episodic memory that can last for a lifetime. As evidenced by the clinical case of the patient HM, memories preserving their episodic nature still depend on the hippocampal formation, several years after being created, while semantic memories are thought to reside in neocortical areas. The neurobiological substrate of one-time learning and life-long storing in the brain, that must exist at the cellular and circuit level, is still undiscovered. The breakthrough is delayed by the fact that studies jointly investigating the rodent hippocampus and entorhinal cortex are mostly targeted at understanding the spatial aspect of learning. Here, we present the concept of an entorhinal cortical module, termed EPISODE module, that could explain how the representations of different elements constituting episodic memories can be linked together at the stage of encoding. The new model that we propose here reconciles the structural and functional observations made in the entorhinal cortex and explains how the downstream hippocampal processing organizes the representations into meaningful sequences. LA - English DB - MTMT ER - TY - JOUR AU - Guerrero, Damaris K. Rangel AU - Donnett, James G. AU - Csicsvari, Jozsef AU - Kovács, Krisztián TI - Tetrode Recording from the Hippocampus of Behaving Mice Coupled with Four-Point-Irradiation Closed-Loop Optogenetics: A Technique to Study the Contribution of Hippocampal SWR Events to Learning JF - ENEURO J2 - ENEURO VL - 5 PB - Society for Neuroscience PY - 2018 IS - 4 PG - 15 SN - 2373-2822 DO - 10.1523/ENEURO.0087-18.2018 UR - https://m2.mtmt.hu/api/publication/30307429 ID - 30307429 AB - With the advent of optogenetics, it became possible to change the activity of a targeted population of neurons in a temporally controlled manner. To combine the advantages of 60-channel in vivo tetrode recording and laser-based optogenetics, we have developed a closed-loop recording system that allows for the actual electrophysiological signal to be used as a trigger for the laser light mediating the optogenetic intervention. We have optimized the weight, size, and shape of the corresponding implant to make it compatible with the size, force, and movements of a behaving mouse, and we have shown that the system can efficiently block sharp wave ripple (SWR) events using those events themselves as a trigger. To demonstrate the full potential of the optogenetic recording system we present a pilot study addressing the contribution of SWR events to learning in a complex behavioral task. LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Krisztián AU - O'Neill, J AU - Schoenenberger, P AU - Penttonen, M AU - Guerrero, DKR AU - Csicsvari, J TI - Optogenetically Blocking Sharp Wave Ripple Events in Sleep Does Not Interfere with the Formation of Stable Spatial Representation in the CA1 Area of the Hippocampus JF - PLOS ONE J2 - PLOS ONE VL - 11 PY - 2016 IS - 10 PG - 19 SN - 1932-6203 DO - 10.1371/journal.pone.0164675 UR - https://m2.mtmt.hu/api/publication/3242015 ID - 3242015 LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Krisztián AU - Steinmann, M AU - Halfon, O AU - Magistretti, PJ AU - Cardinaux, JR TI - Complex regulation of CREB-binding protein by homeodomain-interacting protein kinase 2 JF - CELLULAR SIGNALLING J2 - CELL SIGNAL VL - 27 PY - 2015 IS - 11 SP - 2252 EP - 2260 PG - 9 SN - 0898-6568 DO - 10.1016/j.cellsig.2015.08.001 UR - https://m2.mtmt.hu/api/publication/3242016 ID - 3242016 LA - English DB - MTMT ER - TY - JOUR AU - Pajer, Krisztián AU - Nemes, C AU - Berzsenyi, S AU - Kovács, Krisztián AU - Pirity, Melinda AU - Pajenda, G AU - Nógrádi, Antal AU - Dinnyés, András TI - Grafted murine induced pluripotent stem cells prevent death of injured rat motoneurons otherwise destined to die JF - EXPERIMENTAL NEUROLOGY J2 - EXP NEUROL VL - 269 PY - 2015 SP - 188 EP - 201 PG - 14 SN - 0014-4886 DO - 10.1016/j.expneurol.2015.03.031 UR - https://m2.mtmt.hu/api/publication/2882940 ID - 2882940 N1 - Funding details: 8526-5/2014/TUDPOL, HEALTH-2012-F2-278418, PIAPP-GA-2011-286264, PIAPP-GA-2012-324451, PITN-GA-2012-317146 Funding details: PIAP-GA-2009-251186 Funding details: European Commission, EC Funding details: European Social Fund, ESF Funding text 1: This study was financed by EU FP7 (STEMCAM; PIAP-GA-2009-251186 ; ANISTEM, PIAPP-GA-2011-286264 ; STEMMAD, PIAPP-GA-2012-324451 , EPIHEALTH, HEALTH-2012-F2-278418 ; EPIHEALTHNET, PITN-GA-2012-317146 ), the SZIE Excellence Project (Research Project of Excellence, 8526-5/2014/TUDPOL ) and by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP 4.2.4. A/2-11-1-2012-0001 ‘National Excellence Program’. The authors are indebted to David Durham for critical reading of the manuscript. AB - Human plexus injuries often include the avulsion of one or more ventral roots, resulting in debilitating conditions. In this study the effects of undifferentiated murine iPSCs on damaged motoneurons were investigated following avulsion of the lumbar 4 (L4) ventral root, an injury known to induce the death of the majority of the affected motoneurons. Avulsion and reimplantation of the L4 ventral root (AR procedure) was accompanied by the transplantation of murine iPSCs into the injured spinal cord segment in rats. Control animals underwent ventral root avulsion and reimplantation, but did not receive iPSCs. The grafted iPSCs induced an improved reinnervation of the reimplanted ventral root by the host motoneurons as compared with the controls (number of retrogradely labeled motoneurons: 503 +/- 38 [AR+iPSCs group] vs 48 +/- 6 [controls, AR group]). Morphological reinnervation resulted in a functional recovery, i.e. the grafted animals exhibited more motor units in their reinnervated hind limb muscles, which produced a greater force than that in the controls (50 +/- 2.1% vs 11.9 +/- 4.2% maximal tetanic tension [% ratio of operated/intact side]). Grafting of undifferentiated iPCSs downregulated the astroglial activation within the L4 segment. The grafted cells differentiated into neurons and astrocytes in the injured cord. The grafted iPSCs, host neurons and glia were found to produce the cytokines and neurotrophic factors MIP-1a, IL-10, GDNF and NT-4. These findings suggest that, following ventral root avulsion injury, iPSCs are able to induce motoneuron survival and regeneration through combined neurotrophic and cytokine modulatory effects. LA - English DB - MTMT ER - TY - JOUR AU - Lovrics, Anna AU - Gao, Y AU - Juhasz, B AU - Bock, István AU - Byrne, HM AU - Dinnyés, András AU - Kovács, Krisztián TI - Boolean Modelling Reveals New Regulatory Connections between Transcription Factors Orchestrating the Development of the Ventral Spinal Cord. JF - PLOS ONE J2 - PLOS ONE VL - 9 PY - 2014 IS - 11 PG - 12 SN - 1932-6203 DO - 10.1371/journal.pone.0111430 UR - https://m2.mtmt.hu/api/publication/2796146 ID - 2796146 AB - We have assembled a network of cell-fate determining transcription factors that play a key role in the specification of the ventral neuronal subtypes of the spinal cord on the basis of published transcriptional interactions. Asynchronous Boolean modelling of the network was used to compare simulation results with reported experimental observations. Such comparison highlighted the need to include additional regulatory connections in order to obtain the fixed point attractors of the model associated with the five known progenitor cell types located in the ventral spinal cord. The revised gene regulatory network reproduced previously observed cell state switches between progenitor cells observed in knock-out animal models or in experiments where the transcription factors were overexpressed. Furthermore the network predicted the inhibition of Irx3 by Nkx2.2 and this prediction was tested experimentally. Our results provide evidence for the existence of an as yet undescribed inhibitory connection which could potentially have significance beyond the ventral spinal cord. The work presented in this paper demonstrates the strength of Boolean modelling for identifying gene regulatory networks. LA - English DB - MTMT ER - TY - JOUR AU - Deshmukh, RS AU - Kovács, Krisztián AU - Dinnyés, András TI - Drug discovery models and toxicity testing using embryonic and induced pluripotent stem-cell-derived cardiac and neuronal cells JF - STEM CELLS INTERNATIONAL J2 - STEM CELLS INT VL - 2012 PY - 2012 PG - 9 SN - 1687-966X DO - 10.1155/2012/379569 UR - https://m2.mtmt.hu/api/publication/2053515 ID - 2053515 LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Krisztián AU - Steullet, P AU - Steinmann, M AU - Do, KQ AU - Magistretti, PJ AU - Halfon, O AU - Cardinaux, JR TI - TORC1 is a calcium- and cAMP-sensitive coincidence detector involved in hippocampal long-term synaptic plasticity JF - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA J2 - P NATL ACAD SCI USA VL - 104 PY - 2007 IS - 11 SP - 4700 EP - 4705 PG - 6 SN - 0027-8424 DO - 10.1073/pnas.0607524104 UR - https://m2.mtmt.hu/api/publication/1868725 ID - 1868725 LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Krisztián AU - Steinmann, M AU - Magistretti, PJ AU - Halfon, O AU - Cardinaux, JR TI - C/EBP beta couples dopamine signalling to substance P precursor gene expression in striatal neurones JF - JOURNAL OF NEUROCHEMISTRY J2 - J NEUROCHEM VL - 98 PY - 2006 IS - 5 SP - 1390 EP - 1399 PG - 10 SN - 0022-3042 DO - 10.1111/j.1471-4159.2006.03957.x UR - https://m2.mtmt.hu/api/publication/1868726 ID - 1868726 LA - English DB - MTMT ER -