Ciliary Neurotrophic Factor/therapeutic use; Neuroprotective Agents/therapeutic use; Sciatic Neuropathy/drug therapy; Adipose Tissue, Brown/drug effects; Adipose Tissue, Brown/metabolism; Animals; Animals, Newborn; Axotomy/methods; Body Weight/drug effects; Cell Count/methods; Cells, Cultured; Chick Embryo; Ciliary Neurotrophic Factor/metabolism; Cricetinae; Cricetulus; Dose-Response Relationship, Drug; Ganglia, Spinal/cytology; Green Fluorescent Proteins/genetics; Humans; Motor Neurons/drug effects; Motor Neurons/physiology; Rats; Rats, Wistar; Recombinant Fusion Proteins/metabolism; Recombinant Fusion Proteins/therapeutic use; STAT3 Transcription Factor/metabolism; Sciatic Neuropathy/etiology; Sciatic Neuropathy/physiopathology; Sensory Receptor Cells/drug effects; Sensory Receptor Cells/physiology; Transduction, Genetic/methods; tat Gene Products, Human Immunodeficiency Virus/genetics; tat Gene Products, Human Immunodeficiency Virus/therapeutic use