Epidurally applied DC evokes long-lasting increase in axonal excitability

• Autorzy: Kaczmarek D. , Bolzoni F. , Hammar I. , Jankowska E.
• Języki publikacji: EN

Abstrakty

EN

INTRODUCTION: Epidural stimulation and trans-spinal direct current stimulation (tsDCS) are used in clinical practice for restoring motor functions or pain relief. However, the use of epidural stimulation is limited by low stimulus intensities tolerated by patients. Locally applied cathodal DC was recently demonstrated to increase the excitability of intraspinal preterminal axonal branches for more than one hour. AIM(S): Our aim was to examine whether brief episodes of epidural DC combined with epidural stimulation evokes long-lasting increase in the excitability of myelinated axons within the dorsal columns. METHOD(S): 17 adult rats of both sexes (Wistar, 2–6 months old, 200–450 g) were used in this study. In deeply anaesthetized animals, afferent volleys in sural and peroneal nerve were evoked by epidural stimuli via needle tungsten electrodes positioned in contact with the dura mater within the L1–L3 segments. The effects of cathodal DC (0.8–1.0 μA) on the excitability of skin and muscle sensory fibres were assessed by changes in antidromic compound action potentials. The areas of nerve volleys evoked before, during, and after DC polarization were measured within time windows of 0.3–1.4 ms from their onset. RESULTS: The study revealed that cathodal DC applied via epidural electrodes resulted in a several-fold increases in the number of epidurally activated fibres. The volley area measured after 10 minutes increased by 411±97%, 733±251% and 502±94% following 15–30 s, 1 min and 2 or 5 min of DC application, respectively. Importantly, the increase in the excitability appeared within seconds and remained elevated for more than one hour. CONCLUSIONS: Combining epidural stimulation and trans-spinal DC polarization may improve their clinical outcome. The differences in time course of DC evoked increases in the excitability of nerve fibres in the dorsal columns compared to previously reported effects in pre-terminal axonal branches suggest a new form of plasticity. FINANCIAL SUPPORT: The study was supported by a grant from Stiftelsen Sigurd & Elsa Goljes Minne to Elzbieta Jankowska.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2017
• Tom: 77
• Numer: Suppl.1
• Opis fizyczny: p.103

Twórcy

autor

Kaczmarek D.

• Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
• Department of Neurobiology and Department of Biochemistry, Poznan University of Physical Education, Poznan, Poland

autor

Bolzoni F.

• Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
• Human Physiology Section of the DEPT, Universita degli Studi di Milano, Milano, Italy

autor

Hammar I.

• Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden

autor

Jankowska E.

• Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden