TY - JOUR AU - Kälin, Stefanie AU - Miller, Kelly R AU - Kälin, Roland E AU - Jendrach, Marina AU - Witzel, Christian AU - Heppner, Frank L TI - CNS myeloid cells critically regulate heat hyperalgesia. JO - The journal of clinical investigation VL - 128 IS - 7 SN - 0021-9738 CY - Ann Arbor, Mich. PB - ASCJ M1 - DZNE-2020-06367 SP - 2774-2786 PY - 2018 AB - Activation of non-neuronal microglia is thought to play a causal role in spinal processing of neuropathic pain. To specifically investigate microglia-mediated effects in a model of neuropathic pain and overcome the methodological limitations of previous approaches exploring microglia function upon nerve injury, we selectively ablated resident microglia by intracerebroventricular ganciclovir infusion into male CD11b-HSVTK-transgenic mice, which was followed by a rapid, complete, and persistent (23 weeks) repopulation of the CNS by peripheral myeloid cells. In repopulated mice that underwent sciatic nerve injury, we observed a normal response to mechanical stimuli, but an absence of thermal hypersensitivity ipsilateral to the injured nerve. Furthermore, we found that neuronal expression of calcitonin gene-related peptide (CGRP), which is a marker of neurons essential for heat responses, was diminished in the dorsal horn of the spinal cord in repopulated mice. These findings identify distinct mechanisms for heat and mechanical hypersensitivity and highlight a crucial contribution of CNS myeloid cells in the facilitation of noxious heat. KW - Animals KW - Calcitonin Gene-Related Peptide: physiology KW - Central Nervous System: pathology KW - Central Nervous System: physiopathology KW - Hot Temperature KW - Hyperalgesia: pathology KW - Hyperalgesia: physiopathology KW - Male KW - Mice KW - Mice, Inbred C57BL KW - Mice, Transgenic KW - Microglia: cytology KW - Microglia: physiology KW - Myeloid Cells: pathology KW - Myeloid Cells: physiology KW - Neuralgia: pathology KW - Neuralgia: physiopathology KW - Peptide Fragments: physiology KW - Peripheral Nerve Injuries: pathology KW - Peripheral Nerve Injuries: physiopathology KW - Peripheral Nerves: pathology KW - Peripheral Nerves: physiopathology KW - Spinal Cord Dorsal Horn: pathology KW - Spinal Cord Dorsal Horn: physiopathology KW - Peptide Fragments (NLM Chemicals) KW - calcitonin gene related peptide (1-7) (NLM Chemicals) KW - Calcitonin Gene-Related Peptide (NLM Chemicals) LB - PUB:(DE-HGF)16 C6 - pmid:29634489 C2 - pmc:PMC6025970 DO - DOI:10.1172/JCI95305 UR - https://pub.dzne.de/record/140045 ER -