Low-intensity sciatic nerve-stretch injury increases nociception, anxiety-like behaviors, and astrocyte activity in male Wistar rats

Author(s)

Silva-Cardoso, G. K. ; Bello Jr, P. E. ; Lazarini-Lopes, W. ; Ferrarese-Tiballi, A. A. ; Leite-Panissi, C. R. A.

• Document type: Journal article
• Source: Brazilian Journal of Medical and Biological Research; v. 58, p. 9-pg., 2025-01-01.

Abstract

The incidence of chronic pain in the general population is highly correlated to anxiety disorders, which promote negative effects on the quality of life. Stretch injury is the primary cause of nerve dysfunction and injury in the civilian population. Here, we characterized changes in nociception, anxiogenic-like behaviors, and astrocyte expression in the low-intensity sciatic nervestretch injury (NSI) model. Male Wistar rats were submitted to NSI, chronic constriction injury of the sciatic nerve (CCI), or sham surgery (SHAM). Animals were submitted to nociceptive tests (von Frey, acetone, and hot plate) before surgery and 6, 12, 18, and 24 days post-surgery. Anxiety-like behaviors were assessed in the open field test (OFT) 23 days after surgery. Immunofluorescence for astrocyte activity (glial fibrillary acidic protein (GFAP)) was performed in cortical, thalamic, and brainstem areas involved with pain and emotional processing. Animals submitted to NSI showed increased mechanical allodynia and thermal hyperalgesia, similar to those submitted to CCI. In the OFT, both NSI and CCI animals showed an increase in anxiety-like behaviors. Also, NSI animals presented an increased expression of GFAP in all analyzed areas, similar to CCI animals. In conclusion, the NSI model produced behavioral alterations comparable to those observed in the CCI model, including hypersensitivity to mechanical and thermal (heat) stimuli that lasted for more than three weeks. Additionally, both models induced a similar increase in GFAP expression in cortical, thalamic, and brainstem regions. (AU)

• FAPESP's process: 22/05471-0 - Pain modulation: effects of systemic treatment with cannabidiol and possible mechanisms
• Grantee: Christie Ramos Andrade Leite Panissi
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/12439-3 - Cannabinoids in the amygdala-parabrachial circuit, and the regulation of pain
• Grantee: Gleice Kelli Ribeiro da Silva Cardoso
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 18/06877-5 - Systemic treatment with canabidiol in a neuropathic pain model: evaluation of the sensorial-discriminative and emotional-motivacional components pain sensitivity
• Grantee: Gleice Kelli Ribeiro da Silva Cardoso
• Support Opportunities: Scholarships in Brazil - Doctorate