Age Comparison Of Heteronymous Facilitation And Homosynaptic Depression Of H-reflex During Different Body Weights

2010 ◽  
Vol 42 ◽  
pp. 578-579
Author(s):  
Masaaki Tsuruike ◽  
Koichi Kitano ◽  
David M. Koceja
Keyword(s):  
H Reflex ◽  
Homosynaptic Depression ◽  
Body Weights

Effects of homosynaptic depression on spectral properties of H-reflex recordings

2012 ◽  
Vol 29 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Kristof Kipp ◽  
Samuel T. Johnson ◽  
Mark A. Hoffman
Keyword(s):  
Spectral Properties ◽  
H Reflex ◽  
Homosynaptic Depression

Postactivation Depression of the Soleus H Reflex Measured Using Threshold Tracking

2008 ◽  
Vol 100 (6) ◽  
pp. 3275-3284 ◽  
Author(s):  
Penelope A. McNulty ◽  
Stacey K. Jankelowitz ◽  
Tanya M. Wiendels ◽  
David Burke
Keyword(s):  
Plantar Flexion ◽  
H Reflex ◽  
Homosynaptic Depression ◽  
Threshold Tracking ◽  
Nonlinear Input ◽  
The Face ◽  
Reflex Gain ◽  
Afferent Inputs ◽  
Voluntary Contractions ◽  
Postactivation Depression

The interpretation of changes in the soleus H reflex is problematic in the face of reflex gain changes, a nonlinear input/output relationship for the motoneuron pool, and a nonhomogeneous response of different motoneurons to afferent inputs. By altering the stimulus intensity to maintain a constant reflex output, threshold tracking allows a relatively constant population of α-motoneurons to be studied. This approach was used to examine postactivation (“homosynaptic”) depression of the H reflex (HD) in 23 neurologically healthy subjects. The H reflex was elicited by tibial nerve stimulation at 0.05, 0.1, 0.3, 1, and 2 Hz at rest and during voluntary plantar flexion at 2.5, 5, and 10% of maximum. A computerized threshold tracking procedure was used to set the current needed to generate a target H reflex 10% of Mmax. The current needed to produce the target reflex increased with stimulus rate but not significantly beyond 1 Hz. In three subjects, the current needed to produce H reflexes of 5, 10, 15, and 20% Mmax at 0.3, 1, and 2 Hz increased with rate and with the size of the test H reflex. HD was significantly reduced during voluntary contractions. Using threshold tracking, HD was maximal at lower frequencies than previously emphasized, probably because HD is greater the larger the test H reflex. This would reinforce the greater sensitivity of small motoneurons to reflex inputs.

L-Ascorbic Acid Addition to Chitosan Reduces Body Weight in Overweight Women

2014 ◽  
Vol 84 (1-2) ◽  
pp. 5-11 ◽  
Author(s):  
Eun Y. Jung ◽  
Sung C. Jun ◽  
Un J. Chang ◽  
Hyung J. Suh
Keyword(s):  
Ascorbic Acid ◽  
Body Weight ◽  
Fat Body ◽  
Body Weight Gain ◽  
Skinfold Thickness ◽  
The Body ◽  
Control Group ◽  
Percentage Body Fat ◽  
Overweight Women ◽  
Body Weights

Previously, we have found that the addition of L-ascorbic acid to chitosan enhanced the reduction in body weight gain in guinea pigs fed a high-fat diet. We hypothesized that the addition of L-ascorbic acid to chitosan would accelerate the reduction of body weight in humans, similar to the animal model. Overweight subjects administered chitosan with or without L-ascorbic acid for 8 weeks, were assigned to three groups: Control group (N = 26, placebo, vehicle only), Chito group (N = 27, 3 g/day chitosan), and Chito-vita group (N = 27, 3 g/day chitosan plus 2 g/day L-ascorbic acid). The body weights and body mass index (BMI) of the Chito and Chito-vita groups decreased significantly (p < 0.05) compared to the Control group. The BMI of the Chito-vita group decreased significantly compared to the Chito group (Chito: -1.0 kg/m2 vs. Chito-vita: -1.6 kg/m2, p < 0.05). The results showed that the chitosan enhanced reduction of body weight and BMI was accentuated by the addition of L-ascorbic acid. The fat mass, percentage body fat, body circumference, and skinfold thickness in the Chito and Chito-vita groups decreased more than the Control group; however, these parameters were not significantly different between the three groups. Chitosan combined with L-ascorbic acid may be useful for controlling body weight.

METABOLIC AND ENDOCRINE ASPECTS OF THE WHIRLER MUTATION IN MALE MICE

1970 ◽  
Vol 64 (2) ◽  
pp. 347-358
Author(s):  
A. Stanley Weltman ◽  
Arthur M. Sackler
Keyword(s):  
Locomotor Activity ◽  
Endocrine Function ◽  
Metabolic Rates ◽  
Heterozygous Female ◽  
Endocrine Organ ◽  
General Body ◽  
Adrenocortical Activity ◽  
Body Weights ◽  
Seminal Vesicle Weight ◽  
Eosinophil Counts

ABSTRACT Body weight, metabolic rate, locomotor activity and alterations in endocrine organ activity were noted in recessive homozygous male whirler mice and the phenotypically »normal« heterozygotes. Representative populations of the two types were studied at different age levels. In general, body weights of the whirler mice were consistently and significantly lower. Open-field locomotion studies similarly indicated heightened locomotor activity. Total leukocyte and eosinophil counts were either markedly or significantly lower in the homozygous vs. heterozygous whirler groups. Evaluation of relative organ weights showed significantly increased adrenal weights in whirler mice sacrificed at 14 weeks and 11 months of age. These changes were accompanied by involution of the thymus. Thus, the varied data indicate persistent increased metabolism and adrenocortical activity during the life-span of the whirler mice. Seminal vesicle weight decreases in the whirler males at 11 months suggest lower gonadal function. The findings are in accord with previous studies of alterations in metabolic rates and endocrine function of homozygous whirler vs. heterozygous female mice.

Effects of progesterone induced postmaturity on CBG and pituitary-adrenal activities in the rat foetus

1986 ◽  
Vol 112 (3) ◽  
pp. 396-403 ◽  
Author(s):  
Jean Paul Dupouy ◽  
Alain Chatelain
Keyword(s):  
Binding Capacity ◽  
Sharp Decrease ◽  
Plasma Corticosterone ◽  
Corticosterone Concentration ◽  
Rat Pups ◽  
Body Weights ◽  
Normal Rat ◽  
Severe Jaundice ◽  
High Level ◽  
Subsequent Rise

Abstract. CBG and pituitary-adrenal activities were investigated in intact rat foetuses, in newborns spontaneously delivered by vaginal way and in postmature foetuses from mothers with delayed parturition caused by daily progesterone injection from day 20 of gestation. The postmature foetuses had lower body weights and higher adrenal weights on day 22, 23 and 24 of gestation than newborns of the same conceptional age. The corticosterone binding capacity of the plasma as well as the binding capacity of CBG for corticosterone decreased in intact foetuses for the last 3 days of gestation and stayed very low in pups from day 0 to day 8 postpartum. These parameters decreased more slowly in postmature foetuses; however, the differences between the latter and intact foetuses or newborns were not statistically significant. Similar evolution occurred in intact pregnant and suckling females as well as in females with prolonged gestation. The fall in CBG activity in normal rat pups and the subsequent rise in free steroids could explain a sharp decrease in plasma ACTH levels as well as the drop in adrenal and plasma corticosterone concentration. In foetuses with prolonged gestation, the same phenomenon did not occur. Stress conditions produced by maintaining growing foetuses in utero and the development of severe jaundice maintained high ACTH levels. In contrast, the fall in adrenal and plasma corticosterone concentrations in spite of the high level of circulating ACTH could be mainly due to the progesterone inhibition of the steroidogenic activity of the foetal adrenals.

Postnatal growth rate and gonadal development in circadian tau mutant hamsters reared in constant dim red light

Reproduction ◽  
2000 ◽  
pp. 327-330 ◽  
Author(s):  
RJ Lucas ◽  
JA Stirland ◽  
YN Mohammad ◽  
AS Loudon
Keyword(s):  
Time Course ◽  
Red Light ◽  
Somatic Growth ◽  
Postnatal Growth ◽  
Gonadal Development ◽  
Testicular Development ◽  
Wild Type ◽  
Similar Time ◽  
Syrian Hamsters ◽  
Body Weights

The role of the circadian clock in the reproductive development of Syrian hamsters (Mesocricetus auratus was examined in wild type and circadian tau mutant hamsters reared from birth to 26 weeks of age under constant dim red light. Testis diameter and body weights were determined at weekly intervals in male hamsters from 4 weeks of age. In both genotypes, testicular development, subsequent regression and recrudescence exhibited a similar time course. The age at which animals displayed reproductive photosensitivity, as exhibited by testicular regression, was unrelated to circadian genotype (mean +/- SEM: 54 +/- 3 days for wild type and 59 +/- 5 days for tau mutants). In contrast, our studies revealed a significant impact of the mutation on somatic growth, such that tau mutants weighed 18% less than wild types at the end of the experiment. Our study reveals that the juvenile onset of reproductive photoperiodism in Syrian hamsters is not timed by the circadian system.

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