Quantitative analysis of hindlimbs locomotion kinematics in spinalized rats treated with Tamoxifen plus treadmill exercise.

Locomotion recovery after a spinal cord injury (SCI) includes axon regeneration, myelin preservation and increased plasticity in propriospinal and descending spinal circuitries. The combined effects of tamoxifen and exercise after a SCI were analyzed in this study to determine whether the combination of both treatments induces the best outcome in locomotion recovery. In this study, the penetrating injury was provoked by a sharp projectile that penetrates through right dorsal and ventral portions of the T13-L1 spinal segments, affecting propriospinal and descending/ascending tracts. Intraperitoneal application of Tamoxifen and a treadmill exercise protocol, as rehabilitation therapies, separately or combined, were used. To evaluate the functional recovery, angular patterns of the hip, knee and ankle joints as well as the leg pendulum-like movement (PLM) were measured during the unrestricted gait of treated and untreated (UT) animals, previously and after the traumatic injury (15 and 30days post-injury (dpi)). A pattern (curve) comparison analysis was made by using a locally designed Matlab script that determines the Frechet dissimilarity. The SCI magnitude was assessed by qualitative and quantitative histological analysis of the injury site 30days after SCI. Our results showed that all treated groups had an improvement in hindlimbs kinematics compared to the UT group, which showed a poor gait locomotion recovery throughout the rehabilitation period. The group with the combined treatment (tamoxifen+exercise (TE)) presented the best outcome. In conclusion, tamoxifen and treadmill exercise treatments are complementary therapies for the functional recovery of gait locomotion in hemi-spinalized rats.

Histological evaluation of brain damage caused by crude quinolizidine alkaloid extracts from lupines.

The effects of the intracerebroventricular (ICV) administration of crude extracts of lupin quinolizidine alkaloids (LQAs) were studied in adult rat brain tissue. Mature L. exaltatus and L. montanus seeds were collected in western Mexico, and the LQAs from these seeds were extracted and analyzed by capillary gas chromatography. This LQA extract was administered to the right lateral ventricle of adult rats through a stainless steel cannula on five consecutive days. While control animals received 10 microl of sesame oil daily (vehicle), the experimental rats (10 per group) received 20 ng of LQA from either L. exaltatus or from L. montanus. All the animals were sacrificed 40 h after receiving the last dose of alkaloids, and their brains were removed, fixed and coronal paraffin sections were stained with haematoxylin and eosin. Immediately after the administration of LQA the animals began grooming and suffered tachycardia, tachypnea, piloerection, tail erection, muscular contractions, loss of equilibrium, excitation, and unsteady walk. In the brains of the animals treated with LQA damaged neurons were identified. The most frequent abnormalities observed in this brain tissue were "red neurons" with shrunken eosinophilic cytoplasm, strongly stained pyknotic nuclei, neuronal swelling, spongiform neuropil, "ghost cells" (hypochromasia), and abundant neuronophagic figures in numerous brain areas. While some alterations in neurons were observed in control tissues, unlike those found in the animals treated with LQA these were not significant. Thus, the histopathological changes observed can be principally attributed to the administration of sparteine and lupanine present in the alkaloid extracts.

Alterations of the subcommissural organ in the hydrocephalic human fetal brain.

We have studied the subcommissural organ of two hydrocephalic brains, of 20 and 21 gestational weeks and of two normal brains, aged 19 and 23 gestational weeks. Both hydrocephalic cases presented a size reduction of the subcommissural organ compared to the normal cases; only in one case, there were also alterations of the morphological components of the subcommissural organ, suggesting different pathogenic relationships between hydrocephalus and dysplasia of the subcommissural organ.