NADPH diaphorase neuronal dystrophy in gracile nucleus, cuneatus nucleus and spinal trigeminal nucleus in aged rat

Abstract

NADPH -diaphorase (N-d) activity is commonly used to identify NOS-ergic neurons. In our previous study, Nd positive neuritic dystrophy and spheroid termed aging-related N-d Body is discovered in the lumbosacral spinal cord in the normal aging rats. Histological studies also reveal that N-d positive neurodegenerative changes occur in the gracile nucleus. We re-examined N-d activity in gracile nucleus in aged rat. We found Nd positive neuritic dystrophy and spheroid also occurred in the cuneatus nucleus and spinal trigeminal nucleus. Besides regular coronal section, longitudinal oriented dystrophic neurites were detected in the sagittal and horizontal section in gracile nucleus and dorsal column. We fziurther examined the medullary oblongata with regular classical histology including Golgi staining, immunocytochemistry of NOS and phosphorylated tau protein, neuronal tracing method with wheat germ agglutinin conjugated alexa-fluor-488 through sciatic nerve, and spinal cord transection at thoracic level. Most of N-d positive neuritic dystrophy and spheroid did not showed colocalization with NOS or phosphorylated tau protein. Neuronal tracing and spinal cord transection revealed that N-d dystrophic neurites in gracile nucleus originated from terminal of sensory projection from spinal cord and peripheral somatic input. The results suggested that aging-related N-d dystrophy in the gracile nucleus was unique morphological feature. In conclusion, it was postulated that the N-d dystrophy as a morphological marker of aging degenerative damage in normal aged organisms.

Cervical Discopathy in Idiopathic Trigeminal Neuralgia: More than Coincidence?

“…11 Within a few months of spinal cord injury, NADPHdiphosphorase abnormality is seen in the nucleus cuneatus, nucleus gracilis, and spinal trigeminal tract of rats. 32 Neuropathic pain may be experienced by about 80% of individuals who sustain spinal cord injury. 22,56,57 Some studies have pointed out the role of dorsal root ganglion in neuropathic pain.…”

Cervical Discopathy in Idiopathic Trigeminal Neuralgia: More than Coincidence?

“…It has been reported that any pathology in the spinal cord may cause hyperexcitability in the dorsal horn. [25,26] This might occur through dysregulation of glutamate release, uptake and receptor expression, [25,[27][28][29] dendritic spine remodeling, [30,31] loss of local inhibitory (GABAergic) tone, [32][33][34][35][36] descending (particularly serotonergic) inhibitory input to spinal nociceptive circuitry, [28,39,40] or increased expression of calcium channel subunit. [39] Within a few months of spinal cord injury, NADPH-diphosphorase abnormality is seen in the nucleus cunaetus, nucleus gracilis, and spinal trigeminal tract of rats.…”

“…[39] Within a few months of spinal cord injury, NADPH-diphosphorase abnormality is seen in the nucleus cunaetus, nucleus gracilis, and spinal trigeminal tract of rats. [40] Neuropathic pain may be experienced by about 80% of individuals who sustain spinal cord injury. [41][42][43] Some studies have pointed out the role of dorsal root ganglion in neuropathic pain.…”