Subarachnoid Transplant of the Human Neuronal hNT2.19 Serotonergic Cell Line Attenuates Behavioral Hypersensitivity without Affecting Motor Dysfunction after Severe Contusive Spinal Cord Injury
Figure 8
Sensory behaviors after severe contusive SCI and following transplant of hNT2.19 or hNT2.16 cells in vivo. Rats were injured with a weight drop device (NYU impactor, 25 mm) in a rat model of SCI and chronic behavioral hypersensitivity and motor dysfunction. All animals in the study received CsA (10 mg/kg) 1 day before and for 2 wks after the two-week time point (14 days) when some animals were injected with hNT2.19 or hNT2.6 cells. Animals either received SCI alone, laminectomy alone, or SCI plus hNT2.19 or hNT2.6 cells (106 cells/injection), or laminectomy plus either hNT2.19 or hNT2.6 cells into the subarachnoid space at two weeks after SCI. Animals were tested before the SCI (baseline) and once a week following SCI and treatments for hypersensitivity to tactile (a) or thermal (b) stimuli in hindpaws below the SCI. All animals were examined for chronic behavioral hypersensitivity in the right and left hindpaws, but since resultant scores were not significantly different between hindpaws, data was pooled and averaged. SCI injury negatively affected hindpaw responses. Neither hindpaw recovers normal tactile or thermal responses after SCI alone or with transplant of nonserotonergic hNT2.6 cells by 56 days after the severe contusive spinal injury. Data represent the mean value + SEM ( animals in each group) at each time point before and 56 days after SCI. Only the hNT2.19 cell grafts attenuated tactile allodynia (a) and thermal hyperalgesia (b) induced by SCI. Recovery of behaviors after graft of hNT2.19 cells was near normal at the completion of the experiments.
