The Neurophysiology Unit is engaged since 1982 in experimental brain research while contributing to medical and post-graduate teaching.

RESEARCH INTERESTS

 

Our studies aim to help understanding of the neuronal mechanisms underlying:

 

  1.  Synaptic modification underlying learning and memory
  2.  Circuit properties leading to neuronal synchronization and rhythm generation.
  3.  Epileptogenesis
  4.  Somatosensory processing
  5.  Sleep

The connecting thread of our projects is the exploration of brain rhythms.

CURRENTLY EMPLOYED TECHNIQUES

 

Human sleep EEG and evoked potentials (Kostopoulos group).

Electrophysiology of in vitro perfused rodent brain slices (Papatheodoropoulos group).

The experiments are complemented by modeling and signal analysis software development.

PAST CONTRIBUTIONS

 

  1. In the epileptic mutant tottering mouse, absence seizures are co-inherited with an increase in hippocampal excitability. The change is post synaptic in CA1
  2. but the cable properties of the pyramidal neurons as well as recurrent inhibition remain intact.
  3. Both excitability and recurrent inhibition of hippocampal CA1 pyramidal cells undergo profound, non-linear changes with development and aging.
  4. A single experience of generalized convulsion in mice induces opposite long-term modification in GABA (down-regulation) and adenosine A1 (up-regulation) receptors(observed with both in vitro electrophysiology and quantitative autoradiography). Adenosine receptors are also up-regulated in human temporal lobe epileptic foci. Their decrease in rat kainic acid seizures is following neuronal degeneration. We studied A1R development in vitro.
  5. Simulation studies indicate that generalized cortical hyperexcitability may be a sufficient condition for the transition from spindles to spike and wave discharges by the same cortical circuit in the cat model of absence seizures. Conditions necessary for the transition are suggested including an intact recurrent inhibition.
  6. Mathematical modelling of short-term plasticity phenomena with trains of stimulation at the frog neuromuscular junction, introduces a stochastic particle formulation of the vesicle hypothesis. We modelled similar mechanisms as they appear in hippocampal slices.
  7. The ventral part of hippocampus shows a significant defect in short and long-term memory mechanisms.
  8. Low frequency (~ 2-3 Hz) field activity is spontaneously generated in rat ventral hippocampal slices perfused with normal medium.
  9. Human Somatosensory evoked potentials show variability in space and time of source activation as well as SI - SII interactivity.
  10. Ventral hippocampal slices show weaker recurrent inhibition and a propensity for epileptogenesis.
  11. Developed new technique allowing 3D visualization of electromagnetic brain activity.
  12. Clustering of single trial EEG and MEG SI responses compared the two recording modalities.

LAB MEMBERS

KOSTOPOULOS GROUP

 

George K. Kostopoulos, MD, PhD, Professor and Chairman of Physiology [e-mail]

Vasileios Kokkinos, PhD, Postdoc [e-mail]

Andrew Koupparis, MD, PhD student [e-mail]

Dimitris Sakellariou, MSc, PhD student [e-mail]

Costas Bampos, MSc, PhD student [e-mail]

Vasileios Panagopoulos, MD, PhD student [e-mail]

Aspasia Giannakopoulou, BSc, MSc student [e-mail]

Ioannis Zouridis, BSc, MSc student [e-mail]

Maria Liti, BSc, MSc student [e-mail]

 

PAPATHEODOROPOULOS GROUP

 

Costas Papatheodoropoulos, PhD, Ass. Professor of Physiology-Neurophysiology [e-mail]

Stelios Kouvaros, PhD [e-mail]

Vasileios Papaleonidopoulos, MSc, PhD student [e-mail]

George Trombukis, MSc, PhD student [e-mail]

COLLABORATORS

 

 

 

RECENT PUBLICATIONS

 

2016

Kostopoulos, G. K. (2016). History of Neuroscience in Greece: From Alkmaion to Austerity. European Journal of Neuroscience.

 

Sakellariou, D., Koupparis, A. M., Kokkinos, V., Koutroumanidis, M., & Kostopoulos, G. K. (2016). Connectivity Measures in EEG Microstructural Sleep Elements. Frontiers in neuroinformatics, 10.

 

Cortez, M. A., Kostopoulos, G. K., & Snead, O. C. (2016). Acute and chronic pharmacological models of generalized absence seizures. Journal of neuroscience methods, 260, 175-184.

 

Kouvaros, S., & Papatheodoropoulos, C. (2016). Major dorsoventral differences in the modulation of the local CA1 hippocampal network by NMDA, mGlu5, adenosine A 2A and cannabinoid CB 1 receptors. Neuroscience, 317, 47-64.

 

 

2015

 

Sarantis, K., Tsiamaki, E., Kouvaros, S., Papatheodoropoulos, C., & Angelatou, F. (2015). Adenosine A2A receptors permit mGluR5‐evoked tyrosine phosphorylation of NR2B (Tyr1472) in rat hippocampus: a possible key mechanism in NMDA receptor modulation. Journal of neurochemistry, 135(4), 714-726.

 

Papatheodoropoulos, C. (2015). Striking differences in synaptic facilitation along the dorsoventral axis of the hippocampus. Neuroscience, 301, 454-470.

 

Kouvaros, S., Kotzadimitriou, D., & Papatheodoropoulos, C. (2015). Hippocampal sharp waves and ripples: Effects of aging and modulation by NMDA receptors and L-type Ca 2+ channels. Neuroscience, 298, 26-41.

 

Pofantis, H., Georgopoulos, P., Petrides, T., & Papatheodoropoulos, C. (2015). Differences in paired-pulse inhibition and facilitation in the dentate gyrus and CA3 field between dorsal and ventral rat hippocampus. Brain research, 1608, 21-30.

 

 

2014

 

Pofantis, H., & Papatheodoropoulos, C. (2014). The α5GABAA receptor modulates the induction of long‐term potentiation at ventral but not dorsal CA1 hippocampal synapses. Synapse, 68(9), 394-401.

 

Koupparis, A. M., Kokkinos, V., & Kostopoulos, G. K. (2014). Semi-automatic sleep EEG scoring based on the hypnospectrogram. Journal of neuroscience methods, 221, 189-195.

 

2013

 

Kokkinos, V., Koupparis, A. M., & Kostopoulos, G. K. (2013). An intra-K-complex oscillation with independent and labile frequency and topography in NREM sleep. Frontiers in human neuroscience, 7.

 

Kokkinos, V., Koupparis, A. M., Tsiptsios, D., Kostopoulos, G. K., & Koutroumanidis, M. (2013). Spatiotemporal profiles of focal and generalised spikes in childhood absence epilepsy. Epileptic disorders, 15(1), 14-26.

 

Koupparis, A. M., Kokkinos, V., & Kostopoulos, G. K. (2013). Spindle power is not affected after spontaneous K-complexes during human NREM sleep. PloS one, 8(1), e54343.

 

Giannopoulos, P., & Papatheodoropoulos, C. (2013). Effects of μ‐opioid receptor modulation on the hippocampal network activity of sharp wave and ripples. British journal of pharmacology, 168(5), 1146-1164.

 

Kostopoulos, G. K. (2012). Recent advances in sleep physiology of interest to psychoanalysis. In International Forum of Psychoanalysis (Vol. 21, No. 3-4, pp. 229-238). Taylor & Francis Group.

 

Kokkinos, V., & Kostopoulos, G. K. (2011). Human non‐rapid eye movement stage II sleep spindles are blocked upon spontaneous K‐complex coincidence and resume as higher frequency spindles afterwards. Journal of sleep research, 20(1pt1), 57-72.

 

 

 

 

 

 

 

CONTACT

 

George K. Kostopoulos

Professor and Chairman of Neurophysiology

Department of Physiology

University of Patras Medical School

University Campus Rion, Patras, Greece, PC 26500

Tel. +30-2610-969155 (secr.), +30-2610-969157 (pers.)

Fax. +30-2610-969215

e-mail. gkkostop@upatras.gr

 

 

Costas E. Papatheodoropoulos

Ass. Professor of Physiology-Neurophysiology

Department of Physiology

University of Patras Medical School

University Campus Rion, Patras, Greece, PC 26500

Tel. +30-2610-969155 (secr.), +30-2610-969117 (pers.)

Fax. +30-2610-969215

e-mail. cepapath@upatras.gr

 

 

 

Updated: 08/2016