Left-right side-specific endocrine signaling complements neural pathways to mediate acute asymmetric effects of brain injury

• Published in: eLife 2021-08, Vol.10
• Main Authors: Lukoyanov, Nikolay, Watanabe, Hiroyuki, Carvalho, Liliana S, Kononenko, Olga, Sarkisyan, Daniil, Zhang, Mengliang, Andersen, Marlene Storm, Lukoyanova, Elena A, Galatenko, Vladimir, Tonevitsky, Alex, Bazov, Igor, Iakovleva, Tatiana, Schouenborg, Jens, Bakalkin, Georgy
• Format: Article
• Language: English
• Subjects: Animals; Antagonists; Argipressin; Asymmetry; Basic Medicine; Beta-endorphin; Biological products; Brain; Brain damage; Brain Injuries - metabolism; Brain Injuries - physiopathology; Brain injury; Cortex (motor); Cortex (somatosensory); Drug withdrawal; Gene expression; Hypotheses; Injuries; left-right side; Male; Medical and Health Sciences; Medicin och hälsovetenskap; Medicinska och farmaceutiska grundvetenskaper; Motor neurons; Narcotics; Neural Pathways - metabolism; Neural Pathways - physiology; neuroendocrine signaling; neurohormones; Neurons; Neuroscience; Neurosciences; Neurotransmitters; Neurovetenskaper; nociceptive withdrawal reflex; Opioid receptors; Pituitary; Pituitary hormones; postural asymmetry; Posture; Rats; Rats, Sprague-Dawley; Rats, Wistar; Reflex; Reflexes; Rodents; Sensorimotor Cortex - physiology; Signal transduction; Spinal cord; Spinal cord injuries; Surgery; Thorax; Traumatic brain injury; Vasopressin; Vasopressin receptors
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/ELIFE.65247

Brain injuries can interrupt descending neural pathways that convey motor commands from the cortex to spinal motoneurons. Here, we demonstrate that a unilateral injury of the hindlimb sensorimotor cortex of rats with completely transected thoracic spinal cord produces hindlimb postural asymmetry with contralateral flexion and asymmetric hindlimb withdrawal reflexes within 3 hr, as well as asymmetry in gene expression patterns in the lumbar spinal cord. The injury-induced postural effects were abolished by hypophysectomy and were mimicked by transfusion of serum from animals with brain injury. Administration of the pituitary neurohormones β-endorphin or Arg-vasopressin-induced side-specific hindlimb responses in naive animals, while antagonists of the opioid and vasopressin receptors blocked hindlimb postural asymmetry in rats with brain injury. Thus, in addition to the well-established involvement of motor pathways descending from the brain to spinal circuits, the side-specific humoral signaling may also add to postural and reflex asymmetries seen after brain injury.