Blue Corn Tortillas: Effects on Learning and Spatial Memory in Rats.

Consumption of pigmented corn has been associated with health benefits due to its flavonoid contents (mainly anthocyanins) and antioxidant ability. Therefore, the objective of this study was to determine the effect of blue corn tortilla (BM) consumption on memory and learning ability adult rats. Eighteen adult female rats were divided into three groups and fed for 38 consecutive days with commercial food (Control group) or the commercial food plus 6 g/day of either blue corn (BM) or white corn (WM) tortillas. Memory and learning capabilities were assessed using Barnes's labyrinth at the end of the feeding period. Short-and long-term memory was improved in the BM group, showing that consumption of blue maize tortillas improves learning and memory capabilities in adult rats.

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.

Neuronal damage and changes in the expression of muscarinic acetylcholine receptor subtypes in the neonatal rat cerebral cortical upon exposure to sparteine, a quinolizidine alkaloid.

Sparteine is a quinolizidine alkaloid (QA) produced by Lupine species that has generated much interest due to its anti-hypertensive, anti-pyretic, and anti-inflammatory properties. In the nervous system, sparteine has been shown to display anti-cholinergic and depressive activity, although how sparteine exerts its toxic effects in the brain remains unclear. We have addressed this issue by administering subcutaneous injections of sparteine (25 mg/kg of body weight) to rats on postnatal days 1 and 3, and then examining the expression of the muscarinic acetylcholine receptor (mAChR) subunits m1-m4 in the brains of the neonatal rats 14-60 days later. Administration of sparteine to neonatal rats caused neuronal damage in the cerebral motor cortex accompanied by transient changes in the expression of m1-m4 mAChR subunits as revealed by both RT-PCR and Western blotting. This effect could be prevented by pre-treatment with atropine (10 mg/kg) 1 h prior to the injection of sparteine, suggesting that the cytotoxic activity of sparteine is mediated through mAChRs.

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.

[Regeneration of the axotomised sciatic nerve in dogs using the tubulisation technique with Chitosan biomaterial preloaded with progesterone]. / Regeneracion del nervio ciatico axotomizado del perro mediante la técnica de tubulizacion con el biomaterial quitosana precargado con progesterona.

INTRODUCTION: Injuries to peripheral nerves can have different causes and may lead to disorders affecting mobility, sensitivity and loss of motor function as they progress. Weiss, in 1944, introduced tubulisation to promote the regeneration of a sectioned nerve. In this study the biomaterial Chitosan was used to induce and stimulate the regeneration of the sciatic nerve in dogs. At the same time, we took advantage of the characteristics offered by Chitosan to include the neurosteroid progesterone in its matrix, as a promoter of axonal growth. AIMS. The aim of our study was to determine the degree of regeneration of the sciatic nerve in dogs when axotomised tubulised with a Chitosan prosthesis steeped in the neurosteroid progesterone. MATERIALS AND METHODS: Young adult female dogs were used to evaluate the regeneration of the sciatic nerve induced at a standard of 15 mm; regeneration was determined by means of an axonal growth chamber. Nerve growth was studied through histological analysis and by electron microscope. RESULTS: The statistical analysis showed that there were no significant differences in the number of myelinated fibres between the experimental groups. The electron microscope images of the transmission in the regenerated nerves in the groups that were tubulised with Chitosan, with and without neurosteroid preloading, revealed an advanced regenerative process. This was evidenced by the fact that collagen fibres, elastin, Schwann cells and both myelinated and non myelinated fibres were observed in all cases. CONCLUSIONS: The regeneration of axotomised, tubulised nerves was achieved regardless of the treatment that was applied. The distal nerve segment that was analysed revealed a similar structure to that of a normal nerve.

Immunological study of a chitosan prosthesis in the sciatic nerve regeneration of the axotomized dog.

This study demonstrated that when the regeneration of the axotomized sciatic nerve is induced through tubulization with chitosan, this biomaterial does not induce immunostimulation or immunodepression in the dog. Canine females were distributed among three groups: an intact control group which was only isolated, an axotomized control group, and an axotomized group which was tubulized with 3% chitosan prostheses. In vitro culture and phagocytosis tests, as well as IgG and IgM serum concentrations, were determined in peripheral blood on days 0, 15, 30 and 60. The results showed that chitosan implants did not importantly affect the immune response.

Regeneración del nervio ciático axotomizado del perro mediante la técnica de tubulización con el biomaterial quitosana precargado con progesterona / Regeneration of the axotomixed sciatic nerve in dogs using the tubulisation technique with chitosan biomaterial preloaded with progesterone

Introducción. Los nervios periféricos se pueden lesionar por distintas causas, y causar en el curso de su evolución trastornos de movilidad, sensibilidad y pérdida de la función motora. Weiss, en 1944, introdujo la tubulización para promover la regeneración de un nervio seccionado. En este estudio se utilizó el biomaterial quitosana para inducir y estimular la regeneración del nervio ciático del perro, además de aprovechar la cualidad que presenta la quitosana para incluir en su matriz el neuroesteroide progesterona, como un promotor de crecimiento axónico. Objetivo. Determinar el grado de regeneración del nervio ciático del perro axotomizado-tubulizado con una prótesis de quitosana impregnada del neuroesteroide progesterona. Material y métodos. Se emplearon perros hembra adultos jóvenes para evaluar la regeneración del nervio ciático inducida a un defecto de 15 mm, y se determinó su regeneración a través de la cámara de crecimiento axónico. Los crecimientos nerviosos se estudiaron mediante un análisis histológico y por microscopía electrónica. Resultados. El análisis estadístico indicó que no hubo diferencias significativas en el número de fibras mielinizadas entre los grupos experimentales. La microscopía electrónica de transmisión de los nervios regenerados de los grupos tubulizados con quitosana, con y sin neuroesteroide precargado, indicaron un proceso regenerativo avanzado, puesto que en todos se apreciaron fibras de colágeno, elastina, células de Schwann y fibras mielinizadas y no mielinizadas. Conclusiones. La regeneración de los nervios axotomizados y tubulizados se logró con independencia del tratamiento aplicado. El segmento nervioso distal que se analizó evidenció una estructura similar a la de un nervio normal (AU)

Utilización de prótesis de quitosana y silicona en la regeneración del nervio ciático axotomizado de ratas / Quitosan and silicon protesis of the axiotomized cyatic nerve in rats

Para la tubulización de nervios lesionados se ha utilizado silicona con buenos resultados en defectos menores de 3 cm. La silicona es considerada como un material inerte, pero tiene como inconveniente que no es absorbible y es necesaria una segunda cirugía para retirarla. Recientemente, se ha centrado el interés en la utilización de compuestos bioactivos, tales como, la quitosana, homopolímero de estructura lineal con enlaces1-4, N acetilglucosamina, obtenida de la desacetilación de la quitina. La quitosana es absorbible, hipoalergénica, inmunoestimulante y puede actuar como vehículo para liberación prolongada de compuestos. En este trabajo, fue usada para tubulizar el nervio ciático de ratas, para ello se compararon los efectos de ambas prótesis (silicona y quitosana), se analizó la supervivencia neuronal en el dominio medular del nervio ciático y la recuperación locomotriz por medio del índice funcional del nervio ciático. En ninguno de los grupos de animales tubulizados con quitosana o silicona se encontraron indicios de degeneración neuronal en el dominio medular correspondiente. Los animales tubulizados con prótesis de quitosana presentaron una mejor recuperación funcional, esto indica que las prótesis de quitosana produjeron efectos similares a los que resultaron con silicona. Una de las ventajas inmediatas por el uso de quitosana fue evitar una segunda cirugía para retirar la prótesis; sin embargo, este biomaterial posee muchas otras cualidades que facilitan la recuperación de nervios seccionados, mismas que deberán estudiarse utilizando otras técnicas.

Effects of chronic alcohol intake on the vasopressin content in the hypothalamic paraventricular and supraoptic nuclei of the mouse. An immunohistochemical and morphometric study.

The present study analyses the response of the paraventricular (PVN) and supraoptic (SPO) nuclei of the hypothalamus of the male mouse to chronic alcohol intake by immunohistochemical and morphometric methods. We relate the intensity of the reaction to A-V with the vasopressin content of the nucleus, as all the slides, from the control and experimental groups, were processed at the same time and with the same solutions of the antibodies. We suggest that the accumulation of vasopressin, observed in the alcohol-treated animals, of both hypothalamic nuclei could be related to an inhibition of vasopressin release and/or transport from the SPO and PVN to the neurohypophysis and to an increase in vasopressin synthesis in the SPO as this nucleus shows an increase in its nuclear sizes, an index of the function of the neurons.

Alcohol intake effects on the dorsal vagal complex of the rat: a cellular morphometric study.

We have analyzed the morphometric effects on the dorsal vagal complex (DVC) of the rat of alcohol exposure and/or hypoproteic diet intake during 8 weeks. In the area postrema (AP), alcohol treatment (combined with normal isoproteic or hypoproteic diet) caused a significant decrease in karyometric parameters. In the dorsal motor nucleus of the vagus (DMV) and nucleus tractus solitari (NTS), the alcohol isoproteic intake (AI) produced an increase in neuron size (expressed by an increase in the neuronal nuclear area and the cell/neuropil coefficient). The hypoproteic diets produced a reduction in the global volume of each structure of the DVC which was accompanied by a decrease in global brain volume. These results indicate that after 8 weeks of treatment, alcohol is the main cause of the morphometric alteration found in the DVC, while variations in the amount of protein intake appear to produce global effects on the whole brain.

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.

Laminar distribution and morphology of NADPH-diaphorase containing neurons in the optic tectum of the pigeon.

The laminar distribution and morphology of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) containing neurons is studied in the optic tectum (OT) of the pigeon. NADPH-d positive cells are arranged in three bands: the first band, in the stratum griseum et fibrosum superficiale, sublayer II a, is formed by small marginal and horizontal neurons; the second band is broad and extends throughout layers II i-j and III (stratum griseum centrale); the third band lies around the tectal ventricle, and consists of neurons in the stratum griseum profundum (SGP) and tanycytes. A comparison with Golgi-impregnated sections suggests that most NADPH-d positive cells in the OT have local or intratectal axons, while the large efferent neurons in layers IIj and III are NADPH-d negative. Similarities and differences between NADPH-d containing neurons in the avian OT and the mammalian superior colliculus are discussed. The processes of NADPH-d positive neurons in the SGP and of the tanycytes of the tectal ventricle form dense fascicles traversing the stratum album centrale. They surround and contact the radial blood vessels that originate in the SGP. We discuss the possibility that NADPH-d, or nitric oxide synthase, plays a role in the regulation of local blood flow in the deep tectal layers.

The effects of chronic administration of captopril on the mouse subfornical organ and area postrema.

We have studied by morphometric procedures the chronic effect of captopril on the subfornical organ (SFO) and area postrema (AP) of the adult mouse. Oral administration of captopril does not produce any change in the size of individual nuclei of the ependymocytes and neurons in both centers. However, there are other quantitative effects of captopril on the global volume of the SFO and on the neuropil and vascular elements of both the SFO and AP which present a significant increase. It is suggested that this increase is due to metabolic processes at the level of both circumventricular organs.

[Inhalation of organic solvents during the last third of pregnancy in Sprague-Dawley rats. Somatometric and cerebellar consequences in newborn animals]. / Inhalación de solventes orgánicos durante el último tercio del embarazo de ratas Sprague-Dawley. Consecuencias somatométricas y cerebelosas en neonatos.

Cerebellar morphogenesis as well as somatometric parameters of progenies from mothers exposed to ethyl-ether, chloroform, turpentine or thinner were registered a 24, 48 and 7 hours of age. 1. Mortality rate of 20 and 59% was observed in progenies of thinner or turpentine exposed mothers, correspondingly. 2. Delay of intrauterine growth manifested by body weight, size and cephalic diameter was evident in chloroform exposed groups (P < 0.01). 3. Cerebellar maturation delay was found in thinner or turpentine prenatally exposed litters. 4. The number of Purkinje cells was significantly reduced in ethyl-ether and chloroform exposed groups (P < 0.01). These cells were found less affected by thinner or turpentine exposure (P < 0.01).