Distribution of TRPV1 in the Rat Brain Parenchyma’s CSF Contacting Nucleus and its Expressionin Neuropathic Pain

 

Clinical Imaging and Case Reports

Distribution of TRPV1 in the Rat Brain Parenchyma’s CSF Contacting Nucleus and its Expressionin Neuropathic Pain
Li-Cai Zhang

Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College

Correspondence to Author: Li-Cai Zhang
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.