Excitable Structures

Head of Department

Corr. Memb. Prof. Andon Kossev, DSc

  • E-mail: kossevbio.bas.bg
  • Phone: (359 2) 9793702
  • Fax: (359 2) 8723787
  • Address: “Acad. G. Bonchev” Str., Block 23, Room 219
    Sofia 1113, Bulgaria

Staff

Main research topics

Relationship between intra- and extracellular action potentials of excitable cells: isolated muscle fibres, axons and neurons and estimation of their functional state (electrical, mechanical and enzyme activity) under physical and chemical influences. Experimental and model investigations of the peculiarities of the extracellular potential field generated by single muscle fibres, motor units and synchronized compound muscle action potentials. Association between the muscle structure and the generated myoelectric activity. Single motor unit activity in health and disease and their relevance to the function of the whole muscle. Fatigue of muscle fibres, motor units and whole muscle. Electromyographic assessment of the muscle functional state. Integrative of the neuromuscular system: sensory-motor integration, motor control in health and disease.

Biophysics and mathematical modeling of complex systems – the excitability structures in the human body. Numerical simulations giving an objective interpretation on the abnormalities of the membrane properties in hereditary, chronic and acquired demyelinating neuropathies and neuronopathies in the peripheral nerve system.

Mechanisms of electro-mechanical and pharmaco-mechanical coupling in smooth muscles. Studies implement registration of contractile activity of smooth muscle preparations, recording and analysing the changes in the membrane potential and biophysical properties of transmembrane ionic currents (channels), expressed by single smooth muscle cells.
Neurotransmitter interactions and neuromodulatory role of neuropeptides in normal and pathological conditions.

Experimental Methods

Recording of intra- (microelectrode technique) and extracellular action potentials and muscle fibre contractions, spectro photometry, selective intramuscular recording of single muscle fibers and motor unit potentials, selective surface motor unit action potential measurements, invasive and surface electromyography during isometric contractions and movements, transcranial magnetic stimulation.

Whole-cell voltage-clamp and current-clamp in single smooth muscle cells, registration of contractions in native and skinned smooth muscles, contraction measurements in resistant vessels (Mulvany’s myography), fluorescent imaging of second messengers in living cells.
In vivo brain microdialysis combined with HPLC detection of aminoacids (Asp,Glu,GABA, taurine).

Mathematical Methods

Simulations of double cable model and multi-layered model of the myelin sheath of human motor and sensory nerve fibres.

Research projects

Current projects

  1. A bilateral project funded by BAS, Bulgaria and CNR, Italy between IBPhBME, BAS and University of Florence and  “Nello Carrara” Institute of Applied Physics, Italy , 2010-2012.
  2. Joint project 29/4/10 between IBPhBME BAS and Medical University Varna, 2010-2012.
  3. Bulgarian National Science Fund, Project № DТК 02/35, 2010-2012.
    Coordinator: Assoc. Prof. K. Kolikov

Past projects

International collaboration

  • University of Florence, Florence, Italy
  • Wright State University, Dayton, USA
  • Medical Center, Boston, USA
  • Institute of Neurology, University College London, UK
  • Sport and Exercise Science Research Centre, London South Bank University, UK
  • Medical School of Hannover, Department of Neurology and Clinical Neurophysiology, Germany

Awards

  • 2003 – Diana Stephanova – Award of Bulgarian Ministry of Science and Education
  • 2006 – Mariya Daskalova – Award of Bulgarian Academy of Sciences for young scientists

Selected publications

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