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SUMMARY:Sympathetic Nerve Activity during Deep Brain Stimulation - Dr Yrsa
  Sverrisdottir\, Department of Physiology\, Anatomy and Genetics\, Univers
 ity of Oxford
DTSTART:20130206T163000Z
DTEND:20130206T173000Z
UID:TALK42344@talks.cam.ac.uk
CONTACT:Suzy Blows
DESCRIPTION:Electrical deep brain stimulation (DBS) in humans has previous
 ly been shown to alter cardiovascular parameters such as blood pressure\, 
 pulse pressure and the response of blood pressure to standing. An alterati
 on in the autonomic nervous system is likely to be responsible for these c
 hanges. \nWe have directly recorded sympathetic nerve activity (MSNA) in h
 umans with deep brain stimulating electrodes during on/off stimulation pha
 ses of subcortical structures known to modulate arterial blood pressure. \
 nPatients undergoing deep brain stimulation of the periaqueductal gray (PA
 G) and subthalamic nucleus (STN) for chronic neuropathic pain and Parkinso
 n’s disease\, respectively\, were selected. Our results on the effects o
 f DBS on the STN and PAG show differentiated changes in sympathetic outflo
 w during on/off stimulation periods\, which are reflected in a differentia
 ted hemodynamic response.  \nWhile it is not known how the differentiated 
 control of sympathetic discharge probability and strength is brought about
 \, it has been suggested that baroreflex modulation of sympathetic outflow
  occurs at two CNS locations. The dorsal PAG which is involved in pain reg
 ulation and cardiovascular control is also a major site in processing fear
  and anxiety. Single vasoconstrictor fibre firing probability during rest 
 was recently shown to be increased in patients with panic disorder. A shif
 t towards a greater number of high amplitudes and hence number of fibres f
 iring together as observed during PAG stimulation is in keeping with these
  findings.  Our STN results also suggest this area is an important part of
  the neurocircuitry controlling the arterial baroreflex.\n
LOCATION:Lecture Theatre 1\, Department of Veterinary Medicine
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