Authors:

Li-Cai Zhang

Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College

Abstract:

Background: The ventral periaqueductal central grey (PAG) of the brainstem is home to the cerebrospinal fluidcontacting nucleus (CSF-CN), which may affect the actual composition of the cerebrospinal fluid (CSF) for non-synaptic signal transmission by releasing or absorbing bioactive material. TRPV1 has been identified in areas of the spinal and peripheral nervous systems that are known to play a part in the detection, transmission, and control of pain. Consequently, it is hypothesised that the CSF-CN uses the TRPV1 receptor to engage in pain regulation. The current work aims to examine the expression and distribution of TRPV1 in the rat brain parenchyma’s CSF-CN and the role of TRPV1 in neuropathic pain. Methods: In Spague-Dawley rats, a model of neuropathic pain with chronic sciatic nerve constriction injury (CCI) was created. We measured the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL). In order to investigate CSF-CN, the cholera toxin subunit B conjugated with horseradish peroxidase (CB-HRP) was injected into one of the rats’ lateral ventricles (LV). With the help of immunohistochemistry, TRPV1 and CB-HRP were doublelabeled in order to better understand its distribution and expression in the CSF-CN. At the peak of allodynia and hyperalgesia (10 days following CCI surgery), SB-366791, a specific TRPV1 antagonist, was administered in 5 g into one of the rat’s LVs. Rat behaviour was evaluated at 0, 0.5, 1, 2, 4, and 8 hours before and after injection. Conclusion: TRPV1 is confined to the mesencephalon’s CSF-CN, where CCI surgery has boosted the expression of TRPV1. TRPV1 in CSF-CN has been validated as a viable target for the treatment of neuropathic pain thanks to comparative analgesic effects of a TRPV1 anatagonist in a CCI model of neuropathic pain.
Keywords:
dCSF-CNs; CSF-CN; TRPV1; SB366791; Neuropathic pain

Citation:

Li-Cai Zhang. Distribution of TRPV1 in the Rat Brain Parenchyma’s CSF Contacting Nucleus and its Expressionin Neuropathic Pain. Clinical Imaging and Case Reports 2023.