Dorsal horn synaptosomal content of aspartate, glutamate, glycine and GABA are differentially altered following chronic constriction injury to the rat sciatic nerve.
The present study directly examined the axon terminal (synaptosomal) level of amino acid neurotransmitters in rats following chronic constriction injury (CCI) to the sciatic nerve. Dorsal horn, synaptosomal content of aspartate (Asp), glutamate (Glu), glycine and gamma-aminobutyric acid (GABA) was assessed in these rats, and in normal age-matched and younger rats. The synaptosomal content of Asp and Glu in CCI rats was increased by 44-46% compared with control rats (P<0.016). The synaptosomal content of GABA in younger rats was 33% lower than that observed in control rats (P<0.005). Altered axon terminal levels of amino acid neurotransmitters accompany the painful symptoms of neuropathy. The lower axon terminal level of GABA in younger rats may help to explain the age-dependency of pain development in animal models of nerve injury.
Somers
David L
DL
Department of Physical Therapy, Duquesne University, 304 Health Sciences Building, Pittsburgh, PA 15282, USA. somers@duq.edu
Clemente
F Richard
FR
D000367:Age Factors; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism*; D002422:Causalgia / Q000378:metabolism / Q000503:physiopathology; D015536:Down-Regulation / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism*; D005998:Glycine / Q000378:metabolism*; D006930:Hyperalgesia / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009433:Neural Inhibition / Q000502:physiology*; D017288:Pain Threshold / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000378:metabolism / Q000503:physiopathology; D020671:Posterior Horn Cells / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000293:injuries / Q000378:metabolism / Q000503:physiopathology; D009435:Synaptic Transmission / Q000502:physiology*; D013574:Synaptosomes / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D001224:Aspartic Acid; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D005998:Glycine