When the left side knows something happened to the right - sensing injury in neurons contralateral and remote to injury

• Published in: Neural regeneration research 2020-10, Vol.15 (10), p.1854-1855
• Main Authors: Verge, Valerie, Hasmatali, Jovan, Misra, Vikram
• Format: Article
• Language: English
• Subjects: Binding sites; Biochemistry; Development and progression; Gene expression; Genes; Growth factors; Health aspects; Injuries; Localization; Nervous system diseases; Neurological research; Neurons; Nociception; Pain; Peptides; Physiological aspects; Proteins; Sensory receptors; Transcription factors
• ISSN: 1673-5374; 1876-7958
• DOI: 10.4103/1673-5374.280316

In preclinical investigations, mirror pain (mechanical hypersensitivity) induced in rats by unilateral L5/6 spinal nerve ligation is associated with bilateral increases in nerve growth factor expression in the activated perineuronal satellite glial cells in dorsal root ganglia. Intrathecal delivery of either nerve growth factor antibodies or post-synaptic density-95 short hairpin RNA constructs, the latter to prevent the formation of synapse-like structures, attenuated the creation of the synapse-like structures around large sensory neurons by sympathetic and calcitonin-gene-related peptide sensory fibres and alleviated the mirror pain. Notably, this contralateral loss of innervation remained up to 21 weeks post-injury, but did not result in an altered contralateral algesic state (Oaklander and Brown, 2004). Because this change appeared restricted to the tibial innervation and did not impact the sural innervation patterns they concluded that this response likely does not involve a humoral signal, but may involve rapid transcellular signals, as the changes were evident as early as one day after injury. [...]the creation of a novel transgenic fluorescent reporter mouse that assesses the secondary impacts of peripheral nerve injury, has facilitated examination of how broad reaching the injury-associated effects might be.