The Journal of comparative neurology
-
The majority of spinal cord injuries (SCIs) in the clinic occur at the lower cervical levels, resulting in both white and gray matter disruption. In contrast, most experimental models of SCI in rodents induce damage in the thoracic cord, resulting primarily in white matter disruption. To address this disparity, experimental cervical SCI models have been developed. ⋯ Additionally, post-SCI administration of 17β-estradiol improved skilled forelimb function and locomotor function. Taken together, these data suggest that post-SCI administration of 17β-estradiol protected both the gray and white matter in cervical SCI. Moreover, this treatment improved function on skilled motor tasks that involve both gray and white matter components, suggesting that this is likely a highly clinically relevant protective strategy.
-
Treatment with testosterone is neuroprotective/neurotherapeutic after a variety of motoneuron injuries. Here we assessed whether testosterone might have similar beneficial effects after spinal cord injury (SCI). Young adult female rats received either sham or T9 spinal cord contusion injuries and were implanted with blank or testosterone-filled Silastic capsules. ⋯ Similarly, the vastus lateralis muscle weights and fiber cross-sectional areas of untreated SCI animals were smaller than those of sham-surgery controls, and these reductions were both prevented by testosterone treatment. No effects on motor endplate area or density were observed across treatment groups. These findings suggest that regressive changes in motoneuron and muscle morphology seen after SCI can be prevented by testosterone treatment, further supporting a role for testosterone as a neurotherapeutic agent in the injured nervous system.
-
Binocular deprivation of pattern vision (BD) early in life permanently impairs global motion perception. With the SMI-32 antibody against neurofilament protein (NFP) as a marker of the motion-sensitive Y-cell pathway (Van der Gucht et al. [2001] Cereb. Cortex 17:2805-2819), we analyzed the impact of early BD on the retinal circuitry in adult, perceptually characterized cats (Burnat et al. [2005] Neuroreport 16:751-754). ⋯ In conclusion, we show that the anatomical organization typical of premature Y-type retinal ganglion cells persists into adulthood even if normal visual experience follows for years upon an initial 6-month period of BD. Binocular pattern deprivation possibly induces a lifelong OFF functional domination, normally apparent only during development, putting early high-quality vision forward as a premise for proper ON-OFF pathway segregation. These new observations for pattern-deprived animals provide an anatomical basis for the well-described motion perception deficits in congenital cataract patients.