@article{MTMT:3015678, title = {Intracranial neuronal ensemble recordings and analysis in epilepsy.}, url = {https://m2.mtmt.hu/api/publication/3015678}, author = {Tóth, Emília and Fabó, Dániel and Entz, László and Ulbert, István and Erőss, Loránd}, doi = {10.1016/j.jneumeth.2015.09.028}, journal-iso = {J NEUROSCI METH}, journal = {JOURNAL OF NEUROSCIENCE METHODS}, volume = {260}, unique-id = {3015678}, issn = {0165-0270}, abstract = {Pathological neuronal firing was demonstrated 50 years ago as the hallmark of epileptically transformed cortex with the use of implanted microelectrodes. Since then, microelectrodes remained only experimental tools in humans to detect unitary neuronal activity to reveal physiological and pathological brain functions. This recording technique has evolved substantially in the past few decades; however, based on recent human data implying their usefulness as diagnostic tools, we expect a substantial increase in the development of microelectrodes in the near future. Here, we review the technological background and history of microelectrode array development for human examinations in epilepsy, including discussions on of wire-based and microelectrode arrays fabricated using micro-electro-mechanical system (MEMS) techniques and novel future techniques to record neuronal ensemble. We give an overview of clinical and surgical considerations, and try to provide a list of probes on the market with their availability for human recording. Then finally, we briefly review the literature on modulation of single neuron for the treatment of epilepsy, and highlight the current topics under examination that can be background for the future development.}, year = {2016}, eissn = {1872-678X}, pages = {261-269}, orcid-numbers = {Fabó, Dániel/0000-0001-5141-5351; Ulbert, István/0000-0001-9941-9159; Erőss, Loránd/0000-0002-5796-5546} } @article{MTMT:1349493, title = {Heterogeneous neuronal firing patterns during interictal epileptiform discharges in the human cortex.}, url = {https://m2.mtmt.hu/api/publication/1349493}, author = {Keller, CJ and Truccolo, W and Gale, JT and Eskandar, E and Thesen, T and Carlson, C and Devinsky, O and Kuzniecky, R and Doyle, WK and Madsen, JR and Schomer, DL and Mehta, AD and Brown, EN and Hochberg, LR and Ulbert, István and Halgren, E and Cash, SS}, doi = {10.1093/brain/awq112}, journal-iso = {BRAIN}, journal = {BRAIN}, volume = {133}, unique-id = {1349493}, issn = {0006-8950}, abstract = {Epileptic cortex is characterized by paroxysmal electrical discharges. Analysis of these interictal discharges typically manifests as spike-wave complexes on electroencephalography, and plays a critical role in diagnosing and treating epilepsy. Despite their fundamental importance, little is known about the neurophysiological mechanisms generating these events in human focal epilepsy. Using three different systems of microelectrodes, we recorded local field potentials and single- unit action potentials during interictal discharges in patients with medically intractable focal epilepsy undergoing diagnostic workup for localization of seizure foci. We studied 336 single units in 20 patients. Ten different cortical areas and the hippocampus, including regions both inside and outside the seizure focus, were sampled. In three of these patients, high density microelectrode arrays simultaneously recorded between 43 and 166 single units from a small (4 mm x 4 mm) patch of cortex. We examined how the firing rates of individual neurons changed during interictal discharges by determining whether the firing rate during the event was the same, above or below a median baseline firing rate estimated from interictal discharge-free periods (Kruskal-Wallis one-way analysis, P<0.05). Only 48% of the recorded units showed such a modulation in firing rate within 500 ms of the discharge. Units modulated during the discharge exhibited significantly higher baseline firing and bursting rates than unmodulated units. As expected, many units (27% of the modulated population) showed an increase in firing rate during the fast segment of the discharge (+/-35 ms from the peak of the discharge), while 50% showed a decrease during the slow wave. Notably, in direct contrast to predictions based on models of a pure paroxysmal depolarizing shift, 7.7% of modulated units recorded in or near the seizure focus showed a decrease in activity well ahead (0-300 ms) of the discharge onset, while 12.2% of units increased in activity in this period. No such pre-discharge changes were seen in regions well outside the seizure focus. In many recordings there was also a decrease in broadband field potential activity during this same pre-discharge period. The different patterns of interictal discharge-modulated firing were classified into more than 15 different categories. This heterogeneity in single unit activity was present within small cortical regions as well as inside and outside the seizure onset zone, suggesting that interictal epileptiform activity in patients with epilepsy is not a simple paroxysm of hypersynchronous excitatory activity, but rather represents an interplay of multiple distinct neuronal types within complex neuronal networks.}, year = {2010}, eissn = {1460-2156}, pages = {1668-1681}, orcid-numbers = {Ulbert, István/0000-0001-9941-9159} } @article{MTMT:1234812, title = {The human K-complex represents an isolated cortical down-state.}, url = {https://m2.mtmt.hu/api/publication/1234812}, author = {Cash, SS and Halgren, E and Dehghani, N and Rossetti, AO and Thesen, T and Wang, C and Devinsky, O and Kuzniecky, R and Doyle, W and Madsen, JR and Bromfield, E and Erőss, Loránd and Halász, Péter and Karmos, György and Csercsa, Richárd and Wittner, Lucia and Ulbert, István}, doi = {10.1126/science.1169626}, journal-iso = {SCIENCE}, journal = {SCIENCE}, volume = {324}, unique-id = {1234812}, issn = {0036-8075}, abstract = {The electroencephalogram (EEG) is a mainstay of clinical neurology and is tightly correlated with brain function, but the specific currents generating human EEG elements remain poorly specified because of a lack of microphysiological recordings. The largest event in healthy human EEGs is the K- complex (KC), which occurs in slow-wave sleep. Here, we show that KCs are generated in widespread cortical areas by outward dendritic currents in the middle and upper cortical layers, accompanied by decreased broadband EEG power and decreased neuronal firing, which demonstrate a steep decline in network activity. Thus, KCs are isolated "down-states," a fundamental cortico-thalamic processing mode already characterized in animals. This correspondence is compatible with proposed contributions of the KC to sleep preservation and memory consolidation.}, year = {2009}, eissn = {1095-9203}, pages = {1084-1087}, orcid-numbers = {Erőss, Loránd/0000-0002-5796-5546; Wittner, Lucia/0000-0001-6800-0953; Ulbert, István/0000-0001-9941-9159} } @article{MTMT:109455, title = {Massively parallel recording of unit and local field potentials with silicon-based electrodes}, url = {https://m2.mtmt.hu/api/publication/109455}, author = {Csicsvari, J and Henze, DA and Jamieson, B and Harris, KD and Sirota, A and Barthó, Péter and Wise, KD and Buzsáki, György}, doi = {10.1152/jn.00116.2003}, journal-iso = {J NEUROPHYSIOL}, journal = {JOURNAL OF NEUROPHYSIOLOGY}, volume = {90}, unique-id = {109455}, issn = {0022-3077}, year = {2003}, eissn = {1522-1598}, pages = {1314-1323} }