Peripheral gastric leptin modulates brain stem neuronal activity in neonates

1999 ◽  
Vol 277 (3) ◽  
pp. G626-G630 ◽  
Author(s):  
Chun-Su Yuan ◽  
Anoja S. Attele ◽  
Ji An Wu ◽  
Liu Zhang ◽  
Zhi Q. Shi
Keyword(s):  
Brain Stem ◽  
Old Age ◽  
Neuronal Activity ◽  
Nucleus Tractus Solitarius ◽  
Control Level ◽  
Age Groups ◽  
Neonatal Rat ◽  
Activity Levels ◽  
Significant Difference

Afferent sensory fibers are the primary neuroanatomic link between nutrient-related events in the gastrointestinal tract and the central neural substrates that modulate ingestion. In this study, we evaluated the peripheral gastric effects of leptin (OB protein) on brain stem neuronal activities using an in vitro neonatal rat preparation. We also tested gastric leptin effects as a function of age in neonates. For ∼33% of the nucleus tractus solitarius units observed, gastric leptin (10 nM) produced a significant activation of 188.2 ± 8.6% (mean ± SE) compared with the control level of 100% ( P < 0.01). Concentration-dependent leptin effects have also been shown. The remaining neurons (67%) had no significant response to gastric leptin application. Next, we evaluated the peripheral gastric effects of leptin (10 nM) on brain stem unitary activity in three different age groups (1–2 days old, 3–5 days old, and 7–8 days old) of neonatal rats. In the 1- to 2-day-old and the 3- to 5-day-old groups, we observed that response ratios and activity levels were similar. However, there was a significant difference between the 7- to 8-day-old group and the two younger age groups in both the response ratios and the activation levels. The percentage of activation responses increased from ∼26% in the 1- to 2-day-old and the 4- to 5-day-old age groups to 70% in the 7- to 8-day-old group ( P < 0.05). The level of activation increased from 168.3 ± 2.7% (compared with the control level) in the 1- to 2-day-old and the 4- to 5-day-old age groups to 231.4 ± 11.9% in the 7- to 8-day-old group ( P < 0.01). Our data demonstrate that peripheral gastric leptin modulates brain stem neuronal activity and suggest that gastric leptin has a significantly stronger effect in the 7- to 8-day-old animals than in the younger neonates.

Comparison of Human Thymus Gland between Young and Old Age

2021 ◽  
Vol 15 (6) ◽  
pp. 1907-1909
Author(s):  
Faiza Mehboob ◽  
Ponum Mirani ◽  
M. Kamran Ameer ◽  
Khurram Shabeer ◽  
Muhammad Ali Qamar ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Old Age ◽  
Age Groups ◽  
Young Age ◽  
University Hospital ◽  
P Value ◽  
Old Patients ◽  
Human Thymus ◽  
Group I ◽  
Significant Difference

Aim: Study was conducted to examine the different parameters of human thymus glands of young and old patients and compare the findings between both age groups. Study Design: Comparative/observational study Place and Study: Study was conducted at Anatomy department of Nishtar Medical University Hospital, Multan for duration of six months from 15th January 2020 to 15th July 2020. Methods: Total 54 specimens of human thymus of 54 patients were enrolled in this study. All specimens were divided in to two groups I and II, Group I contains 27 patients with ages <30 years and group II with 27 patients having ages 45 to 60 years. All specimens were fixed in 10% formalin solution and then processed for paraffin embedding. Compare the different parameters such as thickness of interlobular connective tissue and thymic capsule, length and number of Hassal’s corpuscles between both groups. Data was analyzed by SPSS 24.0. Results: In group I 12 (44.44%) patients were ages <15 years and 15 (55.56%) patients were ages >15 years. In group 13 (48.15%) and 14 (51.85%) patients were ages <50 years and >50 years. There was a significant difference observed between both groups regarding thickness of interlobular connective tissue and thymic capsule, quantity and length of Hassal’s corpuscles with p-value <0.05. Conclusion: It is to be concluded that patients with young age had significantly less thickness of thymic capsule and interlobular connective tissue with more in number and decreasing size of Hassal’s corpuscles as compared to old age patients. Keywords: Human Thymus Glands, Young Age, Old Age

P–431 Human oocytes in-vitro maturation efficacy from infancy to adulthood – is there an optimal age?

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
G Karavani ◽  
P Wasserzug-Pash ◽  
T Mordechai-Daniel ◽  
M Klutstein ◽  
T Imbar
Keyword(s):  
Fertility Preservation ◽  
In Vitro Maturation ◽  
Ovarian Tissue ◽  
Age Groups ◽  
Ovarian Tissue Cryopreservation ◽  
Success Rates ◽  
Human Oocytes ◽  
Tertiary Center ◽  
Significant Difference

Abstract Study question Does human oocytes in-vitro maturation (IVM) effectiveness change throughout childhood, adolescence and adulthood in girls and women undergoing fertility preservation via ovarian tissue cryopreservation (OTC) prior to chemo-radiotherapy exposure? Summary answer The optimal age for IVM is from menarche to 25 years, while pre-menarche girls and women older than 30 years have extremely low maturation rates. What is known already In vitro maturation of oocytes from antral follicles seen during tissue harvesting is a fertility preservation technique with potential advantages over OTC, as mature frozen and later thawed oocyte used for fertilization poses decreased risk of malignant cells re-seeding, as compared to ovarian tissue implantation. We previously demonstrated that IVM performed following OTC in fertility preservation patients, even in pre-menarche girls, yields a fair amount of oocytes available for IVM and freezing for future use. Study design, size, duration A retrospective cohort study, evaluating IVM outcomes in chemotherapy naïve patients referred for fertility preservation by OTC that had oocyte collected from the medium with attempted IVM between 2003 and 2020 in a university affiliated tertiary center. Participants/materials, setting, methods A total of 133 chemotherapy naïve patients aged 1–35 years with attempted IVM were included in the study. The primary outcome was IVM rate in the different age groups – pre-menarche (1–5 years and ≥6 years), post-menarche (menarche–17 years), young adults (18–24 years) and adults (25–29 and 30–35 years). Comparison between paired groups for significant difference in the IVM rate parameter was done using the Tukey’s Studentized Range (HSD) Test. Main results and the role of chance A gradual increase in mean IVM rate was demonstrated in the age groups over 1 to 25 years (4.6% (1–5 years), 23.8% (6 years to menarche) and 28.4% (menarche to 17 years), with a peak of 38.3% in the 18–24 years group, followed by a decrease in the 25–29 years group (19.3%), down to a very low IVM rate (8.9%) in the 30–35 years group. A significant difference in IVM rates was noted between the age extremes – the very young (1–5 years) and the oldest (30–35 years) groups, as compared with the 18–24-year group (p &lt; 0.001). Number of oocytes matured, percent of patients with matured oocytes and overall maturation rate differed significantly (p &lt; 0.001). Limitations, reasons for caution Data regarding ovarian reserve evaluation was not available for most of the patients, due to our pre-op OTC procedures protocol. None of our patients have used their frozen in-vitro matured oocytes, as such further implications of age on in-vitro matured oocytes quality and implantation potential has yet to be evaluated. Wider implications of the findings: Our finding of extremely low success rates in those very young (under 6 years) and older (≥30 years) patients suggest that IVM of oocyte retrieved during OTC prior to chemotherapy should not be attempted in these age group. Trial registration number N/A

Neurochemical excitation of propriospinal neurons facilitates locomotor command signal transmission in the lesioned spinal cord

2011 ◽  
Vol 105 (6) ◽  
pp. 2818-2829 ◽  
Author(s):  
Eugene Zaporozhets ◽  
Kristine C. Cowley ◽  
Brian J. Schmidt
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Signal Transmission ◽  
Cholinergic Receptor ◽  
Neonatal Rat ◽  
Receptor Antagonists ◽  
Ion Removal ◽  
Propriospinal Neurons ◽  
Command Signal

Previous studies of the in vitro neonatal rat brain stem-spinal cord showed that propriospinal relays contribute to descending transmission of a supraspinal command signal that is capable of activating locomotion. Using the same preparation, the present series examines whether enhanced excitation of thoracic propriospinal neurons facilitates propagation of the locomotor command signal in the lesioned spinal cord. First, we identified neurotransmitters contributing to normal endogenous propriospinal transmission of the locomotor command signal by testing the effect of receptor antagonists applied to cervicothoracic segments during brain stem-induced locomotor-like activity. Spinal cords were either intact or contained staggered bilateral hemisections located at right T1/T2 and left T10/T11 junctions designed to abolish direct long-projecting bulbospinal axons. Serotonergic, noradrenergic, dopaminergic, and glutamatergic, but not cholinergic, receptor antagonists blocked locomotor-like activity. Approximately 73% of preparations with staggered bilateral hemisections failed to generate locomotor-like activity in response to electrical stimulation of the brain stem alone; such preparations were used to test the effect of neuroactive substances applied to thoracic segments (bath barriers placed at T3 and T9) during brain stem stimulation. The percentage of preparations developing locomotor-like activity was as follows: 5-HT (43%), 5-HT/ N-methyl-d-aspartate (NMDA; 33%), quipazine (42%), 8-hydroxy-2-(di- n-propylamino)tetralin (20%), methoxamine (45%), and elevated bath K+ concentration (29%). Combined norepinephrine and dopamine increased the success rate (67%) compared with the use of either agent alone (4 and 7%, respectively). NMDA, Mg2+ ion removal, clonidine, and acetylcholine were ineffective. The results provide proof of principle that artificial excitation of thoracic propriospinal neurons can improve supraspinal control over hindlimb locomotor networks in the lesioned spinal cord.

Rhythmic sympathetic nerve discharges in an in vitro neonatal rat brain stem-spinal cord preparation

1999 ◽  
Vol 87 (3) ◽  
pp. 1066-1074 ◽  
Author(s):  
Chun-Kuei Su
Keyword(s):  
Spinal Cord ◽  
Ascorbic Acid ◽  
Brain Stem ◽  
Sympathetic Nerve ◽  
Power Spectral Analysis ◽  
Neural Mechanisms ◽  
Neonatal Rat ◽  
Root Activity ◽  
Superior Cerebellar Artery

To understand the origination of sympathetic nerve discharge (SND), I developed an in vitro brain stem-spinal cord preparation from neonatal rats. Ascorbic acid (3 mM) was added into the bath solution to increase the viability of preparations. At 24°C, rhythmic SND (recorded from the splanchnic nerve) was consistently observed, but it became quiescent at <16°C. Respiratory-related SND (rSND) was discernible and was well correlated with C4 root activity. Power spectral analysis of SND revealed a dominant 2-Hz oscillation. In most preparations (86%), such oscillation was persistent, whereas it only slightly reduced its magnitude after isolation from the brain stem. The removal of neural structures rostral to the superior cerebellar artery (equivalent to the level of facial nuclei) reduced rSND, increased tonic SND, but did not affect the temporal coupling between SND and C4 root activity. Our data suggest a prominent contribution of SND from the neural mechanisms confined within the neonatal rat spinal cord. This ascorbic acid-enhanced in vitro preparation is a very useful model to study neural mechanisms underlying sympathorespiratory integration.

Micturition reflexes in the in vitro neonatal rat brain stem-spinal cord-bladder preparation

1994 ◽  
Vol 266 (3) ◽  
pp. R658-R667 ◽  
Author(s):  
K. Sugaya ◽  
W. C. De Groat
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Brain Stem ◽  
Rat Brain ◽  
Bladder Wall ◽  
Spinal Reflex ◽  
Neonatal Rat ◽  
Evoked Contractions ◽  
Stimulation Of

An in vitro neonatal (1-7 day) rat brain stem-spinal cord-bladder (BSB) preparation was used to examine the central control of micturition. Isovolumetric bladder contractions occurred spontaneously or were induced by electrical stimulation of the ventrolateral brain stem, spinal cord, bladder wall (ES-BW), or by perineal tactile stimulation (PS). Transection of the spinal cord at the L1 segment increased the amplitude of ES-BW- and PS-evoked contractions, and subsequent removal of the spinal cord further increased spontaneous and ES-BW-evoked contractions but abolished PS-evoked contractions. Hexamethonium (1 mM), a ganglionic blocking agent, mimicked the effect of cord extirpation. Tetrodotoxin (1 microM) blocked ES-BW- and PS-evoked contractions but enhanced spontaneous contractions. Bicuculline methiodide (10-50 microM), a gamma-aminobutyric acid A receptor antagonist, increased the amplitude of spontaneous, ES-BW- and PS-evoked contractions. These results indicate that PS-evoked contractions are mediated by spinal reflex pathways, whereas spontaneous and ES-BW-evoked contractions that are elicited by peripheral mechanisms are subject to a tonic inhibition dependent on an efferent outflow from the spinal cord. PS-evoked micturition is also subject to inhibitory modulation arising from sites rostral to the lumbosacral spinal cord. Although electrical stimulation of bulbospinal excitatory pathways can initiate bladder contractions in the neonatal rat, these pathways do not appear to have an important role in controlling micturition during the first postnatal week.

Glutamine synthetase expression in rat lung is regulated by protein stability

1998 ◽  
Vol 275 (5) ◽  
pp. L877-L886 ◽  
Author(s):  
Brian I. Labow ◽  
Steve F. Abcouwer ◽  
Cheng-Mao Lin ◽  
Wiley W. Souba
Keyword(s):  
Protein Stability ◽  
Physiological Stress ◽  
Control Level ◽  
Methionine Sulfoximine ◽  
Activity Levels ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Protein Levels ◽  
Gs Protein

During physiological stress, the lung increases production of the amino acid glutamine (Gln) using the enzyme Gln synthetase (GS) to maintain Gln homeostasis. Glucocorticoid hormones are considered the principal mediators of GS expression during stress. However, whereas animal studies have shown that glucocorticoids increase lung GS mRNA levels 500–700%, GS activity levels rise only 20–45%. This discrepancy suggests that a posttranscriptional control mechanism(s) ultimately determines GS expression. We hypothesized that the level of GS protein in the lung is governed by the intracellular Gln concentration through a mechanism of protein destabilization, a feedback regulatory mechanism that has been observed in vitro. To test this hypothesis, Sprague-Dawley rats were treated with a Gln-free diet and the GS inhibitor methionine sulfoximine (MSO) to deplete tissue Gln levels and prevent this feedback regulation. Exposure to Gln-free chow and MSO (100 mg/kg body wt) for 6 days decreased plasma Gln levels 50% ( P < 0.01) and decreased lung tissue Gln levels by 70% ( P < 0.01). Although lung GS mRNA levels were not influenced by Gln depletion, there was a sevenfold ( P < 0.01) increase in GS protein. A parenteral Gln infusion (200 mM, 1.5 ml/h) for the last 2 days of MSO treatment replenished lung Gln levels to 65% of control level and blunted the increase in GS protein levels by 33% ( P < 0.05) compared with rats receiving an isomolar glycine solution. The acute effects of glucocorticoid and MSO administration on lung GS expression were also measured. Whereas dexamethasone (0.5 mg/kg) and MSO injections individually augmented lung GS protein levels twofold and fourfold ( P < 0.05), respectively, the combination of dexamethasone and MSO produced a synergistic, 12-fold induction ( P < 0.01) in lung GS protein over 8 h. The data suggest that, whereas glucocorticoids are potent mediators of GS transcriptional activity, protein stability greatly influences the ultimate expression of GS in the lung.

Reliability of Monosynaptic Sensory Transmission in Brain Stem Neurons In Vitro

2001 ◽  
Vol 85 (5) ◽  
pp. 2213-2223 ◽  
Author(s):  
Mark W. Doyle ◽  
Michael C. Andresen
Keyword(s):  
Brain Stem ◽  
Nucleus Tractus Solitarius ◽  
Temporal Integration ◽  
Second Order ◽  
Failure Rates ◽  
Critical Feature ◽  
Medial Nucleus ◽  
Nmda Glutamate Receptors ◽  
Spatio Temporal

The timing of events within the nervous system is a critical feature of signal processing and integration. In neurotransmission, the synaptic latency, the time between stimulus delivery and appearance of the synaptic event, is generally thought to be directly related to the complexity of that pathway. In horizontal brain stem slices, we examined synaptic latency and its shock-to-shock variability (synaptic jitter) in medial nucleus tractus solitarius (NTS) neurons in response to solitary tract (ST) electrical activation. Using a visualized patch recording approach, we activated ST 1–3 mm from the recorded neuron with short trains (50–200 Hz) and measured synaptic currents under voltage clamp. Latencies ranged from 1.5 to 8.6 ms, and jitter values (SD of intraneuronal latency) ranged from 26 to 764 μs ( n = 49). Surprisingly, frequency of synaptic failure was not correlated with either latency or jitter ( P > 0.147; n = 49). Despite conventional expectations, no clear divisions in latency were found from the earliest arriving excitatory postsynaptic currents (EPSCs) to late pharmacologically polysynaptic responses. Shortest latency EPSCs (<3 ms) were mediated by non– N-methyl-d-aspartate (non-NMDA) glutamate receptors. Longer latency responses were a mix of excitatory and inhibitory currents including non-NMDA EPSCs and GABAa receptor–mediated currents (IPSC). All synaptic responses exhibited prominent frequency-dependent depression. In a subset of neurons, we labeled sensory boutons by the anterograde fluorescent tracer, DiA, from aortic nerve baroreceptors and then recorded from anatomically identified second-order neurons. In identified second-order NTS neurons, ST activation evoked EPSCs with short to moderate latency (1.9–4.8 ms) but uniformly minimal jitter (31 to 61 μs) that were mediated by non-NMDA receptors but had failure rates as high as 39%. These monosynaptic EPSCs in identified second-order neurons were significantly different in latency and jitter than GABAergic IPSCs (latency, 2.95 ± 0.71 vs. 5.56 ± 0.74 ms, mean ± SE, P = 0.027; jitter, 42.3 ± 6.5 vs. 416.3 ± 94.4 μs, P = 0.013, n = 4, 6, respectively), but failure rates were similar (27.8 ± 9.0 vs. 9.7 ± 4.4%, P = 0.08, respectively). Such results suggest that jitter and not absolute latency or failure rate is the most reliable discriminator of mono- versus polysynaptic pathways. The results suggest that brain stem sensory pathways may differ in their principles of integration compared with cortical models and that this importantly impacts synaptic performance. The unique performance properties of the sensory-NTS pathway may reflect stronger axosomatic synaptic processing in brain stem compared with dendritically weighted models typical in cortical structures and thus may reflect very different strategies of spatio-temporal integration in this NTS region and for autonomic regulation.

scholarly journals COMPARATIVE CHARACTERISTICS OF THE PARAMETERS OF THE CEREBELLUM OF MEN AT A YOUNG AND OLD AGE ACCORDING TO MAGNETIC RESONANCE TOMOGRAPHY

2021 ◽  
Vol 28 (4) ◽  
pp. 68-72
Author(s):  
Anatoly A. Balandin ◽  
Lev M. Zheleznov ◽  
Irina A. Balandina ◽  
Valery S. Shelud'ko
Keyword(s):  
Magnetic Resonance ◽  
Old Age ◽  
Age Groups ◽  
Magnetic Resonance Tomography ◽  
Cerebellar Hemisphere ◽  
Morphometric Study ◽  
Age Related ◽  
Group I ◽  
Significant Difference ◽  
The Right

Investigation which devoted to the study of the age characteristics of the human body are becoming increasingly important. Magnetic resonance tomography is the most informative diagnostic method for intravital visualization of tissues and structures of the brain. It also allows you to more accurately see the picture of morphological features with age-associated changes. The aim of the study was to carry out a comparative analysis of the age-related morphometric characteristics of the cerebellum in male with mesocranic type of cranium in young and old age according to the data of magnetic resonance tomography. The analysis of the results of a morphometric study of the cerebellum on tomograms of 91 men examined for medical reasons was carried out. Depending on the age, the subjects were divided into two groups. Group I included 52 young men (22–27 years old, inclusive), group II included 39 elderly men (from 78 to 83 years old, inclusive). The transverse, longitudinal and vertical dimensions of the cerebellum were determined. When comparing the parameters of the linear dimensions of the cerebellum in the studied age groups of men, a statistically significant decrease in all indicators in old age compared with young age was revealed (p=0.042). There was no statistically significant difference between the parameters of the longitudinal and vertical sizes of the cerebellar hemispheres in individuals of each age group (p>0.05); there is a tendency for these sizes to prevail in the right cerebellar hemisphere. The results obtained can serve as the equivalent of the age-related anatomical norm of the cerebellum in young and old men, which will make it possible to use these data in basic and clinical research, as well as in medical practice.

Vagal interactions on brain stem neurons receiving input from the proximal stomach in cats

1990 ◽  
Vol 258 (2) ◽  
pp. G320-G327 ◽  
Author(s):  
William D. Barber ◽  
Chun-Su Yuan ◽  
Brian J. Cammarata
Keyword(s):  
Brain Stem ◽  
Nucleus Tractus Solitarius ◽  
Recording Site ◽  
Proximal Stomach ◽  
Neuronal Interactions ◽  
Afferent Fibers ◽  
Significant Difference ◽  
The Mean ◽  
Vagal Afferent ◽  
The Brain

Gastric vagal fibers on the proximal stomach that join the dorsal and ventral vagal trunks were electrically stimulated to localize and evaluate brain stem neuronal interactions in anesthetized cats. The brain stem responses were located in nucleus tractus solitarius in the dorsomedial, caudal region of the medulla oblongata. There was no significant difference in the mean latency of the gastric vagally evoked brain stem response between the dorsal and ventral vagal trunks. The responses consisted of single or multiple spikes with a mean latency of ap290 ± 50 (SD) ms. Forty-one percent, or 168 unitary responses of the 406 total responses recorded, showed convergence of proximal gastric vagal input from both the dorsal and ventral vagal trunks on the same recording site or on the same cell. Of those unitary responses that received convergent proximal gastric vagal input, 95 unitary responses (57%) showed convergence of input to the same area, on different cells at the same recording site during a single trial. Seventy-three single units (43%) received convergent input from proximal gastric vagal afferent fibers in both the dorsal and ventral trunks. Fifty-two, or 7l%, of the single unit convergent responses were excitatory in nature, whereas the remaining 29% were inhibitory. These data demonstrated that proximal gastric vagal afferent fibers that join the dorsal and ventral trunks converged on a significant number of single neurons in the brain stem. The convergent response was synaptically secure and exerted an identifiable biasing effect on the response of the brain stem neuron. These convergent interactions may play an important role in reflex mechanisms concerned with adaptive relaxation to accommodate the ingested content by the proximal stomach. gastric; proximal gastric vagal; ventral vagus; dorsal vagus; nucleus tractus solitarius; vagal brain stem interactions Submitted on March 14, 1988 Accepted on September 19, 1989

scholarly journals Effect of tooth age on bond strength to dentin

2003 ◽  
Vol 11 (4) ◽  
pp. 342-347 ◽  
Author(s):  
Marcelo Giannini ◽  
Patrícia Chaves ◽  
Marcelo Tavares de Oliveira
Keyword(s):  
Bond Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Age Groups ◽  
In Vitro Study ◽  
Adhesive System ◽  
Tensile Bond Strength ◽  
Significant Difference ◽  
Diamond Saw

This in vitro study evaluated the effect of tooth age on the tensile bond strength of Prime & Bond NT adhesive system to dentin. Human third molars from the five age groups were analyzed: A- 17 to 20yrs, B- 21 to 30yrs, C- 31 to 40yrs, D- 41 to 50yrs and E- 51 to 63yrs. The occlusal enamel was removed using a diamond saw under water cooling and the dentin surface was wet-ground with 600-grit SiC paper to obtain flat surfaces. The adhesive system was applied according to the manufacturer's instructions and a 6-mm high resin "crown" was built-up with resin composite. Teeth were stored for 24 hours in distilled water at 37ºC and prepared for micro-tensile testing. Each specimen was mounted in a testing jig attached to a universal testing machine and stressed in tension at a crosshead speed of 0.5mm/min until failure. The means of tensile bond strength were (MPa): A- 21.42 ± 7.52ª; B- 30.13 ± 10.19ª; C- 31.69 ± 11.78ª; D- 30.69 ± 8.47ª and E- 35.66 ± 9.54ª. No statistically significant difference was observed among the age groups (p > 0.05). The results suggested that the tensile bond strength of the adhesive system was not significantly affected by dentin aging.

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