Sweating disorders in mice with and without nerve lesions.

Area of Science:

• Neuroscience
• Pain Research
• Autonomic Nervous System Function

Background:

• Neuropathy patients frequently exhibit hypersensitivity and abnormal sweating patterns.
• Nerve lesions cause sudomotor (sweating) dysfunction, but sweating disorders also appear in complex regional pain syndrome (CRPS), even without a direct nerve lesion.

Purpose of the Study:

• To investigate sweat output and hypersensitivity in mice with nerve lesions versus bone fractures.
• To correlate sweating changes with behavioral hypersensitivity and weight-bearing capacity.

Main Methods:

• Proton nuclear magnetic resonance of sweat water was used to quantify sweat output in mice.
• Mice models included nerve lesions and bone fractures without nerve lesions.
• Sweating was correlated with hypersensitivity (von Frey tests, water application) and weight-bearing (incapacitance meter).

Main Results:

• Nerve-lesioned mice showed reduced sweating and hypersensitivity compared to controls.
• Fractured mice exhibited decreased sweating acutely but increased sweating chronically post-injury.
• Fractured mice displayed both acute and chronic hypersensitivity, resembling human bone trauma and CRPS patients.

Conclusions:

• Sweating abnormalities are observed in both neuropathic and non-neuropathic bone fracture models.
• Autonomic dysfunction is implicated as a significant factor in the development of neuropathies.
• Changes in sweat output following bone trauma in mice may indicate processes leading to human CRPS.