The content of gonadotropin-releasing hormone (GnRH), kisspeptin, and estrogen receptors (ERα/ERß) in the anteromedial hypothalamus displays daily variations throughout the rat estrous cycle.

The content of gonadotropin-releasing hormone (GnRH), its mRNA, and estrogen receptor alpha (ERα) and beta (ERß) in the hypothalamus varies throughout the estrous cycle. Furthermore, the abundance of these molecules displays asymmetry between the right and left side. In the present study, we investigated the changes in the content of ERα, ERß, kisspeptin, and GnRH by western blot in the left and right anteromedial hypothalamus, at four different times during each stage of the rat estrous cycle. The serum levels of the follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were also measured. ERα and ERß levels changed depending on the stage of the estrous cycle, meanwhile that of kisspeptin was modified according to both the hour of the day and the stage of the cycle. Except in estrus day, ERß was higher in the right hypothalamus, while ERα was similar in both sides. During both proestrus and estrus, the content of kisspeptin and GnRH was higher in the right hypothalamus. The highest levels of FSH and LH occurred at 17:00 h of proestrus. But at estrus, the highest FSH levels were observed at 08:00 h and the lowest at 17:00 h. Thus, the current results show that the content of ERα, ERß, kisspeptin, and GnRH in the anteromedial hypothalamus are regulated as a function of the stage of the estrous cycle and the hour of the day. Furthermore, the content of these proteins is regularly higher in the right anteromedial hypothalamus, regardless of the stage of the cycle or time of the day.

Estrogen Receptors Alpha and Beta in POA-AHA Region Regulate Asymmetrically Ovulation.

We examined the role of the estrogen receptors alpha (ERα) and beta (ERß) in of the preoptic-anterior hypothalamic area (POA-AHA) in the regulation of ovulation in rats. The number of ERα- and ERß-immunoreactive (-ir) cells was determined at 09:00, 13:00, and 17:00 h of each stage of the estrous cycle in intact rats. Additionally, the effects of blocking ERα and ERß on ovulation rate at 09:00 h on diestrus-2 or proestrus day through the microinjection of methyl-piperidino-pyrazole (MPP) or cyclofenil in either side of POA-AHA were evaluated. The number of ERα-ir and ERß-ir cells in POA-AHA varied in each phase of estrous cycle. Either MPP or cyclofenil in the right side of POA-AHA on diestrus-2 day reduced the ovulation rate, while at proestrus day it was decreased in rats treated in either side with MPP, and in those treated with cyclofenil in the left side. MPP or cyclofenil produced a decrease in the surge of luteinizing hormone levels (LH) and an increase in progesterone and follicle stimulating hormone (FSH). Replacement with synthetic luteinizing hormone-releasing hormone in non-ovulating rats treated with MPP or cyclofenil restored ovulation. These results suggest that activation of estrogen receptors on the morning of diestrus-2 and proestrus day asymmetrically regulates ovulation and appropriately regulates the secretion of FSH and progesterone in the morning and afternoon of proestrus day. This ensures that both, the preovulatory secretion of LH and ovulation, occur at the right time.

Muscarinic Receptors Types 1 and 2 in the Preoptic-Anterior Hypothalamic Areas Regulate Ovulation Unequally in the Rat Oestrous Cycle.

Muscarinic receptors types 1 (m1AChR) and 2 (m2AChR) in the preoptic and anterior hypothalamus areas (POA-AHA) were counted, and the effects of blocking these receptors on spontaneous ovulation were analysed throughout the rat oestrous cycle. Rats in each phase of the oestrous cycle were assigned to the following experiments: (1) an immunohistochemical study of the number of cells expressing m1AChR or m2AChR in the POA-AHA and (2) analysis of the effects of the unilateral blockade of the m1AChR (pirenzepine, PZP) or m2AChR (methoctramine, MTC) on either side of the POA-AHA on the ovulation rate. The number of m2AChR-immunoreactive cells was significantly higher at 09:00 h on each day of the oestrous cycle in the POA-AHA region, while no changes in the expression profile of m1AChR protein were observed. The ovulation rate in rats treated with PZP on the oestrous day was lower than that in the vehicle group. Animals treated on dioestrous-1 with PZP or MTC had a higher ovulation rate than those in the vehicle group. In contrast, on dioestrous-2, the MTC treatment decreased the ovulation rate. These results suggest that m1AChR or m2AChR in the POA-AHA could participate in the regulation of spontaneous ovulation in rats.

The participation of the muscarinic receptors in the preoptic-anterior hypothalamic areas in the regulation of ovulation depends on the ovary.

BACKGROUND: Muscarinic receptors (mAChRs) of the preoptic and anterior hypothalamus areas (POA-AHA) regulate ovulation in an asymmetric manner during the estrous cycle. The aims of the present study were to analyze the effects of a temporal blockade of mAChRs on either side of the POA-AHA performed in diestrus-2 rats on ovulation, the levels of estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) and the mechanisms involved in changes in ovulation. METHODS: Cyclic rats on diestrus-2 day were anesthetized and randomly assigned to the following groups: 1) microinjection of 1 µl of saline or atropine solution (62.5 ng) in the left or right POA-AHA; 2) removal (unilateral ovariectomty, ULO) of the left (L-ULO) or right (R-ULO) ovary, and 3) rats microinjected with atropine into the left or right POA-AHA plus L-ULO or R-ULO. The ovulation rate and the number of ova shed were measured during the predicted estrus, as well as the levels of estradiol, FSH and LH during the predicted proestrus and the effects of injecting synthetic LH-releasing hormone (LHRH) or estradiol benzoate (EB). RESULTS: Atropine in the left POA-AHA decreased both the ovulation rate and estradiol and LH levels on the afternoon of proestrus, also LHRH or EB injection restored ovulation. L- or R-ULO resulted in a lower ovulation rate and smaller number of ova shed, and only injection of LHRH restored ovulation. EB injection at diestrus-2 restored ovulation in animals with L-ULO only. The levels of estradiol, FSH and LH in rats with L-ULO were higher than in animals with unilateral laparotomy. In the group microinjected with atropine in the left POA-AHA, ovulation was similar to that in ULO rats. In contrast, atropine in the right POA-AHA of ULO rats blocked ovulation, an action that was restored by either LHRH or EB injection. CONCLUSIONS: These results indicated that the removal of a single ovary at noon on diestrus-2 day perturbed the neuronal pathways regulating LH secretion, which was mediated by the muscarinic system connecting the right POA-AHA and the ovaries.

Effects of unilaterally microinjecting ethanol in the preoptic-anterior hypothalamic areas of rats on ovulation.

BACKGROUND: Intragastric or intraperitoneal ethanol (EtOH) treatment inhibits reproductive functions in females and male rats. The area of the hypothalamus where these effects take place is unknown. As the participations of the preoptic-anterior hypothalamic area (POA-AHA) in regulating ovulation is asymmetric, this study aims to analyze the effects on 17ß-estradiol(E2 ), progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) serum levels, the messenger ribonucleic acid (mRNA) expression of estrogen receptor alpha (ERα) and beta (ERß), and ovulation resulting from unilaterally microinjecting water or an EtOH solution into either side of the POA-AHA. METHODS: The treatment consisted of microinjecting a 8.6 µM EtOH solution into either side of the POA-AHA. The study was performed on groups of adult cyclic rats at 09.00 hours on diestrus-1, and sacrificed on diestrus-2 at 13.00, on proestrus at 09.00 or 17.00 or on estrus at 09.00 hours. Ovulation rates were assessed in rats sacrificed on estrus. Hormonal serum levels were measured using radioimmunoassay, and as a function of ERα and ERß mRNA expression in each side of the POA-AHA by reverse transcriptase polymerase chain reaction. RESULTS: EtOH treatment blocked ovulation and the preovulatory release of LH, and lowered E2 levels. Irrespective of the treated POA-AHA side, ERα mRNA expression was consistently lower in the left POA-AHA and higher on the right. EtOH treatment in the left POA-AHA decreased FSH serum levels and lowered ERß mRNA expression. In turn, EtOH treatment on the right POA-AHA resulted in higher FSH levels and ERß mRNA expression. CONCLUSIONS: The present results show that EtOH blocks the preovulatory surge of LH on the POA-AHA. The effects of EtOH treatment of preovulatory FSH surge on the POA-AHA are asymmetric (stimulative on the right and inhibiting in the left). The effects of EtOH treatment on preovulatory LH and FSH surge could be explained by the inhibition of ERα and ERß mRNA expression, respectively.

Estandarización de la Figura de Taylor en población mexicana / Taylor's Figure Standardization on Mexican population

In order to perform a neuropsychologycal evaluation, the clinician may use several instruments; nevertheless, most of them have been designed for use on populations with very different social and cultural backgrounds from that of Mexico. This makes the research on the standardization of methods of evaluation for Mexican population a very important task for both clinical and research settings. Normative data obtained from Mexican population is necessary because it provides the clinician that works with Mexican patients with a reference framework that allows him or her to correctly classify a particular behavior of an individual as normal or abnormal and thus make specific evaluations and cooperate in diagnostic. Researchers interested on cognitive functioning also require qualitative and quantitative equivalent instruments that may allow them to objectively evaluate the efficacy of short-time interventions as in a pre- and post-treatment experimental designs; and it is precisely for this reason that Taylor's figure was developed. Taylor's figure (TF) was originally designed as an alternative to Rey-Osterrieth's complex figure (ROCF), in order to use it in test-retest situations. Similar to ROCF, Taylor's figure has two modalities: copy and memory. The former evaluates constructional praxia, while the latter measures immediate recalling. Parallel tests, that is, different tests that evaluate the same variables, are useful because they reduce the measurement error involved in applying the task twice to the same person (i.e. learning), thus increasing the validity of follow up evaluations of cognitive functioning. <

Dentro del ámbito neuropsicológico existe una serie de instrumentos de evaluación que en su mayoría han sido diseñados en un contexto sociocultural diferente al nuestro, por lo que es importante contar con pruebas neuropsicológicas estandarizadas en sujetos mexicanos. Desde esta perspectiva, los datos de una población normativa nos permiten tener un marco de referencia para comparar y establecer diagnósticos diferenciales dentro de la práctica clínica. Asimismo, dentro del ámbito de la investigación se requieren instrumentos que en teoría sean equivalentes en cuanto a la función que evalúan para llevar un seguimiento sobre el funcionamiento cognoscitivo de una población en particular a lo largo del tiempo. La Figura de Taylor se diseñó como una alternativa a la Figura Compleja de Rey-Osterrieth para aplicarla en situaciones de test-retest. Consta de dos modalidades: una de copia que evalúa la praxia de construcción y otra de memoria inmediata. El término <

The acute effects of bilateral ovariectomy or adrenalectomy on progesterone, testosterone and estradiol serum levels depend on the surgical approach and the day of the estrous cycle when they are performed.

Bilateral ovariectomy or adrenalectomy are experimental tools used to understand the mechanisms regulating the hypothalamus-pituitary-ovarian and the hypothalamus-pituitary-adrenal axis. There is evidence that acute unilateral perforation of the dorsal peritoneum in rats results in significant changes in progesterone, testosterone and estradiol serum concentrations. Because different surgical approaches for unilateral or bilateral ovariectomy or adrenalectomy, sectioning the superior ovarian nerve or the vagus nerve are used, we compare the acute effects on hormone serum concentrations resulting from the unilateral or bilateral dorsal approach to performing bilateral ovariectomy or adrenalectomy with those obtained when an unilateral incision is performed in the ventral abdomen. In general, the progesterone, testosterone and estradiol serum concentrations were higher in animals with ventral approach than in those with dorsal surgery, the effects varying depending on the day of the estrous cycle when surgery was performed. The results suggest that the neural signals arising from different zones of the peritoneum and/or the abdominal wall play different roles in the mechanisms regulating steroid hormones concentrations.

Asymmetrical effects of the unilateral implant of pilocarpine on the preoptic-anterior hypothalamic area on spontaneous ovulation of the adult rat

The effects on ovulation at the next strus after unilaterally implanting pilocarpine in the preoptic-anterior hypothalamic area (POA-AHA) of rats on each day of the estrous cycle were analyzed. Implantation on the left side of POA-AHA on the day of estrus blocked ovulation in all animals, whereas implantation on the right side did not (0/5 vs. 4/4, p<0.05). Implantation on diestrus 1 or 2 on either side of the POA-AHA blocked ovulation. Implatation on the righ side of the POA-AHA at the day of proestrus blocked ovulation (1/6 animals ovulated), while 10/12 with pilocarpine on the left side ovulated (p<0.05).The administration of 3.7 µg of GnRH at 13:00 h o the expected day of proestrus induced ovulation in 36/42 treated animals. In rat with a pilocarpine implant, the injection of estradiol benoznate on diestrus 2 restored ovulation only in those animals with the pilocarpine implant placed in the left side of the POA-AHA, performed on the day of estrus. The results support the previous estatements that in the adult rat POA-AHA, the cholinergic mechanism regulating preovulatory GnRH release, is lateralized. In addition, at the beginning of the estrous phase, the PAO-AHA-cholinergic system needs to remain undisturbed for normal ovulation to take place at the next estrus

Modifications on the ovarian response to gonadotropins induced by catecholamine depletion in vagotomized adult rats

Con el fin de estudiar la participación de las catecolaminas (CA) en el proceso del crecimiento folicular y la ovulación en el animal adulto, se analizaron los efectos de la depleción aguda de CA por la administración de reserpina (RSP) (1 mg/KG) sobre la respuesta ovulatoria de animales tratados con FSH y LH. Dado que previamente se mostró que la sección bilateral de los nervios vago provoca aumento en el número de ovocitos liberados por animal ovulante se analizaron los efectos de la vagotomía bilateral previa a la denervación aguda provocada por RSP. La inyección de RSP 3 horas antes de la administración de FSH provocó aumento del número de ovocitos liberados (21.49 ñ 2.87 vs 11.84 ñ 1.58, P < 0.01), del peso de los ovarios (66.20 ñ 4.41 vs. 49.79 ñ 3.99 mg/100 peso corporal, P < 0.01) y disminución del número de folículos preovulatorios. En los animales tratados con RSP 3 horas antes que recibieran LH (53 horas después que fueron tratados con FSH) no se observaron cambios significativos en el número de ovocitos, ni en el peso de los ovarios, en relación con los testigos tratados con FSH y LH. La sección previa (20 días de los nervios vago bloqueó los efectos de la administración de RSP antes de la FSH (ovocitos 5.21 ñ 1.51 vs. 21.49 ñ 2.87, P < 0.001; peso de los ovarios 36.51 ñ 2.38 vs. 66.20 ñ 4.41 mg/100 g, P < 0.001). La sección bilateral de los nervios vago no modificó los resultados obtenidos por la administración de RSP antes de LH. Los resultados del presente estudio sugieren que en condiciones normales las CA tendrían efectos inhibidores sobre el número de receptores foliculares a FSH, mientras que no parecen intervenir en los receptores a LH vinculados al proceso de ovulación. El hecho que la sección bilateral de los nervios vago revierta los efectos de la inyección de RSP antes de la FSH sugiere que en condiciones normales la información que llevan los nervios vago al ovario es agonista con las CA