Intrarectal administration of hCG (Human Choriogonadotropin) and fat loss as assessed by Dual energy X-ray absorptiometry (DXA) in experimental animals.

Our studies suggest that in experimental animals, submitted to a hypocaloric diet, the intrarectal administration of hCG (Human Chorionic Gonadotropin) decreases body fat and increases lean mass content in relative values to a greater extent that control animals who did not receive hCG.
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Multielectrode Recordings From Identified Neurons Involved in Visually Elicited Escape Behavior

A major challenge in current neuroscience is to understand the concerted functioning of distinct neurons involved in a particular behavior. This goal first requires achieving an adequate characterization of the behavior as well as an identification of the key neuronal elements associated with that action. Such conditions have been considerably attained for the escape response to visual stimuli in the crab Neohelice. During the last two decades a combination of in vivo intracellular recordings and staining with behavioral experiments and modeling, led us to postulate that a microcircuit formed by four classes of identified lobula giant (LG) neurons operates as a decision-making node for several important visually-guided components of the crab’s escape behavior. However, these studies were done by recording LG neurons individually. To investigate the combined operations performed by the group of LG neurons, we began to use multielectrode recordings. Here we describe the methodology and show results of simultaneously recorded activity from different lobula elements. The different LG classes can be distinguished by their differential responses to particular visual stimuli. By comparing the response profiles of extracellular recorded units with intracellular recorded responses to the same stimuli, two of the four LG classes could be faithfully recognized. Additionally, we recorded units with stimulus preferences different from those exhibited by the LG neurons. Among these, we found units sensitive to optic flow with marked directional preference. Units classified within a single group according to their response profiles exhibited similar spike waveforms and similar auto-correlograms, but which, on the other hand, differed from those of groups with different response profiles. Additionally, cross-correlograms revealed excitatory as well as inhibitory relationships between recognizable units. Thus, the extracellular multielectrode methodology allowed us to stably record from previously identified neurons as well as from undescribed elements of the brain of the crab. Moreover, simultaneous multiunit recording allowed beginning to disclose the connections between central elements of the visual circuits. This work provides an entry point into studying the neural networks underlying the control of visually guided behaviors in the crab brain.Fil: Cámera, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Belluscio, Mariano Andres. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tomsic, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin

Metabolic Activity of Human Chorionic Gonadotropin (hCG) on Glycemia and Leptinemia in Experimental Animals Fed a Cafeteria Diet

Objectives: To elucidate the relationship of hCG administration to glycemia, Non Esterified Fatty Acids (NEFA), leptin and adiponectin levels on experimental animals previously submitted to a cafeteria diet, and then to a Low Calorie Diet (LCD). Design: Forty-one rats were selected (21 females, 20 males) and divided into seven (0-6) groups. Animals from groups 1 to 6 were fed a "cafeteria diet" with a mean energy content of 10% protein, 30% carbohydrate and 60% fat. Animals from group 0 were fed the standard laboratory diet. After the fattening period, animals from groups 1 to 6 were submitted to a restricted diet consisting of one-third the average daily intake for rats. hCG was administered for five weeks according to a specific protocol. The effects of hCG treatment were evaluated using analysis of variance (ANOVA). Results: These assessments were compared: (1) glycemia, adiponectins, leptins and non-esterified fatty acids (NEFA); (2) weight; (3) formulation effect; and (4) dose effect. Differences in leptins were observed between the Control group and Injectable A (p=0.026), Intrarectal Suspension A (p=0.20), Intrarectal Suspension B (p<0.001), and Intrarectal Suspension C (p<0001) groups. In all cases, the average values were higher for the control group. Significant differences were found in the groups treated with Injectable B, Intrarectal Suspension B (p=0.025) and Intrarectal Suspension C (p=0.037). Groups receiving Intrarectal Suspension B or C showed significantly lower mean leptin values. Differences in glycemia were detected between the Control group and Intrarectal Suspension A (p=0.021) and Intrarectal Suspension B (p=0.020) groups. Groups treated with Intrarectal Suspension A or B showed lower mean blood glucose values. Conclusions: Results show the activity of hCG (both urinary and recombinant) on glycemia and leptins levels in experimental animals in different formulations.hCG administration significantly decreased blood sugar and leptin levels, whereas adiponectins were only relatively sensitive to hCG

Maternal Behavior is Impaired in Female Mice Lacking Type 3 Adenylyl Cyclase

Although chemosensory signals generated by mouse pups may trigger maternal behavior of females, the mechanism for detection of these signals has not been fully defined. As some odorant receptors are coupled to the type 3 adenylyl cyclase (AC3), we evaluated the role of AC3 for maternal behavior using AC3−/− female mice. Here, we report that maternal behavior is impaired in virgin and postpartum AC3−/− mice. Female AC3−/− mice failed the pup retrieval assay, did not construct well-defined nests, and did not exhibit maternal aggression. Furthermore, AC3−/− females could not detect odorants or pup urine in the odorant habituation test and were unable to detect pups by chemoreception. In contrast to wild-type mice, AC activity in main olfactory epithelium (MOE) preparations from AC3−/− female mice was not stimulated by odorants or pheromones. Moreover, odorants and pheromones did not evoke electro-olfactogram (EOG) responses in the MOE of AC3−/− female mice. We hypothesize that the detection of chemical signals that trigger maternal behavior in female mice depends upon AC3 in the MOE

The hypothalamic genesis of obesity

The theories on obesity genesis shifted during the past years from the simple conception of "just overeating" to data supporting the diencephalic origin of the disease. Summarized findings on this issue are displayed

The influence of different excipients and storage procedures on hCG (human Corionic Gonadotropin) as evidenced by spectrophotometry

Our studies concluded that changes in either PH, temperature, electrolytes, excipients, alcohol or silver modify the chemical structure of hCG as evidenced by UV-Spectrophotometry