title: Central circuits regulating the sympathetic outflow to lumbar muscles in spinally transected mice by retrograde transsynaptic transport.
abstract: Despite considerable interest in the mechanisms that control the hyperalgesia associated with muscle inflammation, the CNS descending pathways that coordinate autonomic circuits regulating lumbar muscles are not adequately understood. Here we used both pseudorabies virus (PRV)-614 retrograde transsynaptic tracing and spinally transected method in 33 C57BL/6J mice to map the polysynaptic pathways between lumbar muscle and CNS. Tissues were processed for dual-label immunocytochemical detection between PRV-614 and tryptophan hydroxylase (TPH) or tyrosine hydroxylase (TH)-expressing neurons in CNS. In intact mice, PRV-614 was transported to the intermediolateral column (IML) and ventral horn (VH) of spinal cord, with subsequent transport to many brain regions, including the medullary raphe nuclei, rostral ventrolateral medulla (RVLM), A5 cell group regions (A5), locus coeruleus (LC), the medullary and pontine reticular formation nucleus (MRN and PRN), paraventricular nucleus of the hypothalamus (PVN), and other central sites. However, PRV-614 in spinally transected mice produced retrograde infection of IML, with subsequent transport to main brain regions that have been shown to contribute to regulating sympathetic circuits, including RVLM, Lateral paragigantocellular reticular nucleus (LPGi), A5, LC, and PVN, whereas PRV-614 labeling in VH and MRN was eliminated in almost every case. In above five brain regions, dual-labeling immunocytochemistry showed coexpression of PRV-614/TPH and PRV-614/TH immunoreactive (IR) neurons involved in these regulatory circuits. Our results reveal a hierarchical organization of central autonomic circuits controlling the lumbar muscles, thus providing neuroanatomical substrates for the central catecholaminergic and serotonergic system to regulate the lumbar muscles.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, Hubei, PR China.
authors.forename: Hong-Bing
authors.initials: HB
authors.lastname: Xiang
authors.affiliation: Department of Anesthesiology and Pain Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, Hubei, PR China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Anesthesiology and Pain Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, Hubei, PR China.
authors.forename: Tao-Tao
authors.initials: TT
authors.lastname: Liu
authors.affiliation: Hepatobiliary Surgery Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430022, Hubei, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xiong
mesh_terms: D000320:Adrenergic Fibers / Q000502:physiology*; D000344:Afferent Pathways / Q000033:anatomy & histology* / Q000503:physiopathology; D000818:Animals; D019771:Axotomy; D064131:Back Muscles / Q000294:innervation* / Q000503:physiopathology; D001921:Brain / Q000033:anatomy & histology* / Q000821:virology; D011558:Herpesvirus 1, Suid; D006930:Hyperalgesia / Q000503:physiopathology; D007150:Immunohistochemistry; D007249:Inflammation / Q000503:physiopathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
keywords: Lumbar muscles; pseudorabies virus; spinal transection; tryptophan hydroxylase; tyrosine hydroxylase