Some Autonomic Deficits of Acute or Chronic Cervical Spinal Contusion Reversed by Interim Brainstem Stimulation

Alberto A. Vitores, Stephanie S. Sloley, Catalina Martinez, Melissa M. Carballosa-Gautam, Ian Hentall

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Prolonged electrical stimulation of the hindbrain's nucleus raphe magnus (NRM) or of its major midbrain input region, the periaqueductal gray (PAG), was previously found in rats to promote recovery from sensory-motor and histological deficits of acute thoracic spinal cord injury (SCI). Here, some visceral deficits of acute and chronic midline cervical (C5) contusion are similarly examined. Cranially implanted wireless stimulators delivered intermittent 8 Hz, 30-70 A cathodal pulse trains to a brainstem microelectrode. Injured controls were given inactive stimulators; rats without injuries or implants were also compared. Rectal distension or squeezing of the forepaws caused an exaggerated rise in mean arterial pressure in injured, untreated rats under anesthesia on post-injury week 6, probably reflecting autonomic dysreflexia (AD). These pressor responses became normal when 7 days of unilateral PAG stimulation was started on the injury day. Older untreated injuries (weeks 18-19) showed normal pressor responses, but unexpectedly had significant resting and nociceptive bradycardia, which was reversed by 3 weeks of PAG stimulation started on weeks 7 or 12. Subsequent chronic studies examined gastric emptying (GE), as indicated by intestinal transit of gavaged dye, and serum chemistry. GE and fasting serum insulin were reduced on injury weeks 14-15, and were both normalized by ∼5 weeks of PAG stimulation begun in weeks 7-8. Increases in calcitonin gene-related peptide, a prominent visceral afferent neurotransmitter, measured near untreated injuries (first thoracic segment) in superficial dorsal laminae were reversed by acutely or chronically initiated PAG stimulation. The NRM, given 2-3 weeks of stimulation beginning 2 days after SCI, prevented abnormalities in both pressor responses and GE on post-injury week 9, consistent with its relaying of repair commands from the PAG. The descending PAG-NRM axis thus exhibits broadly restorative influences on visceral as well as sensory-motor deficits, improving chronic as well as acute signs of injury.

Original languageEnglish (US)
Pages (from-to)560-572
Number of pages13
JournalJournal of Neurotrauma
Volume35
Issue number3
DOIs
StatePublished - Feb 1 2018

Fingerprint

Periaqueductal Gray
Contusions
Brain Stem
Wounds and Injuries
Gastric Emptying
Thoracic Injuries
Spinal Cord Injuries
Autonomic Dysreflexia
Visceral Afferents
Rhombencephalon
Calcitonin Gene-Related Peptide
Microelectrodes
Bradycardia
Mesencephalon
Serum
Electric Stimulation
Neurotransmitter Agents
Fasting
Arterial Pressure
Coloring Agents

Keywords

  • AD
  • calcitonin gene-related peptide
  • electrical stimulation
  • GE
  • insulin
  • NRM
  • PAG

ASJC Scopus subject areas

  • Clinical Neurology

Cite this

Some Autonomic Deficits of Acute or Chronic Cervical Spinal Contusion Reversed by Interim Brainstem Stimulation. / Vitores, Alberto A.; Sloley, Stephanie S.; Martinez, Catalina; Carballosa-Gautam, Melissa M.; Hentall, Ian.

In: Journal of Neurotrauma, Vol. 35, No. 3, 01.02.2018, p. 560-572.

Research output: Contribution to journalArticle

Vitores, AA, Sloley, SS, Martinez, C, Carballosa-Gautam, MM & Hentall, I 2018, 'Some Autonomic Deficits of Acute or Chronic Cervical Spinal Contusion Reversed by Interim Brainstem Stimulation', Journal of Neurotrauma, vol. 35, no. 3, pp. 560-572. https://doi.org/10.1089/neu.2017.5123
Vitores, Alberto A. ; Sloley, Stephanie S. ; Martinez, Catalina ; Carballosa-Gautam, Melissa M. ; Hentall, Ian. / Some Autonomic Deficits of Acute or Chronic Cervical Spinal Contusion Reversed by Interim Brainstem Stimulation. In: Journal of Neurotrauma. 2018 ; Vol. 35, No. 3. pp. 560-572.
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