Identifying the substrate for successful robot rehabilitation in adult rats spinalized as neonates: the role of the trunk in locomotor recovery after complete low-thoracic transection

2021 ◽  
Author(s):  
Ubong Ime Udoekwere
2020 ◽  
Vol 21 (15) ◽  
pp. 5520
Author(s):  
Anna Kwaśniewska ◽  
Krzysztof Miazga ◽  
Henryk Majczyński ◽  
Larry M. Jordan ◽  
Małgorzata Zawadzka ◽  
...  

Intraspinal grafting of serotonergic (5-HT) neurons was shown to restore plantar stepping in paraplegic rats. Here we asked whether neurons of other phenotypes contribute to the recovery. The experiments were performed on adult rats after spinal cord total transection. Grafts were injected into the sub-lesional spinal cord. Two months later, locomotor performance was tested with electromyographic recordings from hindlimb muscles. The role of noradrenergic (NA) innervation was investigated during locomotor performance of spinal grafted and non-grafted rats using intraperitoneal application of α2 adrenergic receptor agonist (clonidine) or antagonist (yohimbine). Morphological analysis of the host spinal cords demonstrated the presence of tyrosine hydroxylase positive (NA) neurons in addition to 5-HT neurons. 5-HT fibers innervated caudal spinal cord areas in the dorsal and ventral horns, central canal, and intermediolateral zone, while the NA fiber distribution was limited to the central canal and intermediolateral zone. 5-HT and NA neurons were surrounded by each other’s axons. Locomotor abilities of the spinal grafted rats, but not in control spinal rats, were facilitated by yohimbine and suppressed by clonidine. Thus, noradrenergic innervation, in addition to 5-HT innervation, plays a potent role in hindlimb movement enhanced by intraspinal grafting of brainstem embryonic tissue in paraplegic rats.


1984 ◽  
Vol 247 (3) ◽  
pp. G231-G239
Author(s):  
C. Gespach ◽  
Y. Cherel ◽  
G. Rosselin

Development of cAMP responses to secretin, pancreatic glucagon, and histamine was measured in gastric glands of fetal (day 20), postnatal (days 1-30), and adult rats (day 65). cAMP stimulation by these hormones was already detected on day 20 of gestation. cAMP generation showed biphasic variations during the 1st days of life and at the onset of weaning (day 20). Anticipated weaning at day 14 triggered precocious maturation (efficacies) of the cAMP-generating systems sensitive to secretin, glucagon, and histamine without changing the potencies of the hormones. During development, the general characteristics (potency and pharmacological or regulatory properties) of the receptor-cAMP systems studied were comparable with those evidenced in adult rats. At days 5, 20, and 65, vasoactive intestinal peptide and the peptide having N-terminal histidine and C-terminal isoleucine amide (PHI) were about 100 times less potent than secretin (EC50 = 1.5 X 10(-9) M secretin). The histamine action could be blocked by the competitive H2-receptor antagonist cimetidine (70-100% inhibition) as well as by the noncompetitive inhibitor somatostatin (37-62% inhibition). The data indicate that these regulatory hormones (secretin, glucagon(s), histamine, and somatostatin) might have a direct effect on gastric glands and may modulate their biological activities (metabolism, differentiation, proliferation, and exocrine and endocrine secretions) from the neonatal period in rats. The important physiological role of weaning on the final maturation of the cAMP-generating systems in rat gastric glands is underlined.


2020 ◽  
Vol 129 (6) ◽  
pp. 1310-1323
Author(s):  
Jennifer L. Magnusson ◽  
Craig A. Emter ◽  
Kevin J. Cummings

The role of serotonin in arterial blood pressure (ABP) regulation across states of vigilance is unknown. We hypothesized that adult rats devoid of CNS serotonin (TPH2−/−) have low ABP in wakefulness and NREM sleep, when serotonin neurons are active. However, TPH2−/− rats experience higher ABP than TPH2+/+ rats in wakefulness and REM only, a phenotype present only in older males and not females. CNS serotonin may be critical for preventing high ABP in males with aging.


1989 ◽  
Vol 66 (1) ◽  
pp. 14-19 ◽  
Author(s):  
K. H. Myburgh ◽  
T. D. Noakes ◽  
M. Roodt ◽  
F. S. Hough

The role of moderate exercise in the prevention of high-turnover osteoporosis was investigated by the use of an animal model. The effect of chronic training on gravimetric, mineral, physical, and histological parameters of normal bone was also examined. Fifty-six adult female Long-Evans rats were divided into four groups: sedentary (C) and exercising controls (E) and sedentary (O) and exercising osteoporotics (EO). Exercising animals ran 4 h/wk for 1 yr. Two percent NH4Cl added to drinking water induced osteoporosis as shown by significantly lower femoral density and breaking strength and histomorphometrically quantified tibial trabecular bone volume but a normal mineral-to-matrix ratio in the O rats. The development of high-turnover osteoporosis in O rats was confirmed by significantly higher alkaline phosphatase activity (P less than 0.05), urinary hydroxyproline content (P less than 0.01), resorption surfaces (P less than 0.01), and histological parameters of bone formation (P less than 0.01). Exercise prevented all these biochemical, biophysical, and histological abnormalities in the EO group. Exercise had no influence on the density of normal femurs but tended to increase their breaking strength (by 11%) compared with femurs of C rats (P = 0.11).


2019 ◽  
Vol 1 (4) ◽  
pp. 13-28
Author(s):  
Abdelmonem Awad Hegazy ◽  
Manal Mohammad Morsy ◽  
Rania Said Moawad ◽  
Gehad Mohammad Elsayed

Background Hypothyroidism is a metabolic disorder affecting the functions of many tissues in the body including the testis. Testis is rich in the polyunsaturated fatty acids content and lacks strong intrinsic antioxidant system making it prone to such oxidative stress. L-carnitine (LC) regulates long chain fatty acids metabolism; and is considered a valuable antioxidant factor. Aim It was to evaluate the effect of hypothyroidism induced by propylthiouracil (PTU) on rats’ testes and the possible protective role of LC. Methods Forty-eight adult male albino rats were used in this work. The animals were divided into three groups with sixteen animals in each. Group 1 (Control): Animals were kept without medications. Group 2 (PTU-treated): was subjected to administration of PTU; while group 3 (PTU and LC) received both PTU and LC. By the end of the experiment “30 days”, blood samples were taken for hormonal assay; then animals were anaesthetized and sacrificed. Specimens were homogenized for biochemical analysis; epididymal content of each rat was obtained immediately for semen analysis. Testes’ specimens were harvested, prepared and examined by light microscope examination. Results Induced hypothyroidism was noticed to cause histopathological, morphometric and biochemical changes in rat’s testes. LC protected the testicular specimens against such changes; it also improved the seminal quality and quantity as well as testicular structure and biochemistry. Conclusion Hypothyroidism could result in hazards to the structure of testis. Fortunately co-administration of LC might reduce such hazards.


1974 ◽  
Vol 12 (2) ◽  
pp. 177-198 ◽  
Author(s):  
Rebekah L. Smith ◽  
Thomas Parks ◽  
Gary Lynch

2019 ◽  
Vol 20 (6) ◽  
pp. 1318 ◽  
Author(s):  
Alexandra Kupke ◽  
Sabrina Becker ◽  
Konstantin Wewetzer ◽  
Barbara Ahlemeyer ◽  
Markus Eickmann ◽  
...  

Mammalian Bornavirus (BoDV-1) typically causes a fatal neurologic disorder in horses and sheep, and was recently shown to cause fatal encephalitis in humans with and without transplant reception. It has been suggested that BoDV-1 enters the central nervous system (CNS) via the olfactory pathway. However, (I) susceptible cell types that replicate the virus for successful spread, and (II) the role of olfactory ensheathing cells (OECs), remained unclear. To address this, we studied the intranasal infection of adult rats with BoDV-1 in vivo and in vitro, using olfactory mucosal (OM) cell cultures and the cultures of purified OECs. Strikingly, in vitro and in vivo, viral antigen and mRNA were present from four days post infection (dpi) onwards in the olfactory receptor neurons (ORNs), but also in all other cell types of the OM, and constantly in the OECs. In contrast, in vivo, BoDV-1 genomic RNA was only detectable in adult and juvenile ORNs, nerve fibers, and in OECs from 7 dpi on. In vitro, the rate of infection of OECs was significantly higher than that of the OM cells, pointing to a crucial role of OECs for infection via the olfactory pathway. Thus, this study provides important insights into the transmission of neurotropic viral infections with a zoonotic potential.


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 567
Author(s):  
Wenyu Si ◽  
Hailing Li ◽  
Tiezhu Kang ◽  
Jing Ye ◽  
Zhiqiu Yao ◽  
...  

This study explored the role of γ-aminobutyric acid transaminase (GABA-T) in the puberty and reproductive performance of female rats. Immunofluorescence technique, quantitative real-time PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the distribution of GABA-T and the expression of genes and hormones in female rats, respectively. The results showed that GABA-T was mainly distributed in the arcuate nucleus (ARC), paraventricular nucleus (PVN) and periventricular nucleus (PeN) of the hypothalamus, and in the adenohypophysis, ovarian granulosa cells and oocytes. Abat mRNA level at 28 d was lowest in the hypothalamus and the pituitary; at puberty, it was lowest in the ovary. Abat mRNA level was highest in adults in the hypothalamus; at infancy and puberty, it was highest in the pituitary; and at 21 d it was highest in the ovary. After vigabatrin (GABA-T irreversible inhibitor) was added to hypothalamus cells, the levels of Abat mRNA and Rfrp-3 mRNA were significantly reduced, but Gnrh mRNA increased at the dose of 25 and 50 μg/mL; Kiss1 mRNA was significantly increased but Gabbr1 mRNA was reduced at the 50 μg/mL dose. In prepubertal rats injected with vigabatrin, puberty onset was delayed. Abat mRNA, Kiss1 mRNA and Gnrh mRNA levels were significantly reduced, but Rfrp-3 mRNA level increased in the hypothalamus. Vigabatrin reduced the concentrations of GABA-T, luteinizing hormone (LH) and progesterone (P4), and the ovarian index. Lactation performance was reduced in adult rats with vigabatrin treatment. Four hours after vigabatrin injection, the concentrations of GABA-T and LH were significantly reduced in adult and 25 d rats, but follicle-stimulating hormone (FSH) increased in 25 d rats. In conclusion, GABA-T affects the reproductive function of female rats by regulating the levels of Gnrh, Kiss1 and Rfrp-3 in the hypothalamus as well as the concentrations of LH and P4.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Z. Ardi ◽  
A. Richter-Levin ◽  
L. Xu ◽  
X. Cao ◽  
H. Volkmer ◽  
...  

Abstract Pre-pubertal stress increases post-traumatic stress disorder (PTSD) susceptibility. We have previously demonstrated that enriched environment (EE) intervention immediately after pre-pubertal stress protects from the effects of trauma in adulthood. Here, we examined whether exposure to EE would also be beneficial if applied after exposure to trauma in adulthood. We have recently shown that exposure to juvenile stress and under-water trauma (UWT) is associated with increased expression of GABAA receptor subunit α1 in the ventral hippocampus. However, differentiating between affected and unaffected individuals, this increased expression was confined to stress-exposed, behaviorally unaffected individuals, suggesting upregulation of α1 expression as a potential mechanism of resilience. We now examined whether EE-induced resilience renders increased expression of α1 in the ventral hippocampus redundant when facing a trauma later in life. Adult rats were exposed to UWT, with pre-exposure to juvenile stress, and tested in the open field and elevated plus maze paradigms four weeks later. EE exposure during juvenility prevented pre-pubertal stress-induced vulnerability, but not if performed following UWT in adulthood. Furthermore, juvenile EE exposure prevented the trauma-associated increase in α1 expression levels. Our findings emphasize the importance of early interventions in order to reduce the likelihood of developing psychopathologies in adulthood.


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