Phys Occup Ther Pediatr
February 2017
Aims: To evaluate the effects of hippotherapy on physical capacities of children with cerebral palsy.
Methods: Thirteen children (4-12 years old) with cerebral palsy classified in Gross Motor Function Classification System Level I or II were included in this prospective quasi-experimental ABA design study. Participants received 10 weeks of hippotherapy (30 min per week).
This study assessed the lasting impact of dexamethasone (DEX) exposure during early development on tissue repair capacity at later life stages (5, 14, and 24 days post fertilization [dpf]) in zebrafish larvae. Using the caudal fin amputation model, we show that prior exposure to DEX significantly delays but does not prevent wound healing at all life stages studied. DEX-induced impairments on wound healing were fully restored to normal levels with longer post amputation recovery time.
View Article and Find Full Text PDFWe applied an acute stress model to zebra fish in order to measure the changes in the metabolome due to biological stress. This was done by submitting the fish to fifteen minutes of acute confinement (netting) stress, and then five minutes for the open field and light/dark field tests. A polar extract of the zebra fish was then subjected to (1)H nuclear magnetic spectroscopy.
View Article and Find Full Text PDFProlonged maternal separation (MS) activates the neonate's hypothalamus-pituitary-adrenal axis causing elevated basal and stress-induced corticosterone levels that may initiate amygdala-dependent fear learning. Here we test the hypothesis that the adult fearful phenotype is programmed by the pup's stressful experience during prolonged MS rather than by prolonged maternal absence per se. For this purpose, Wistar rat pups were exposed, on postnatal-day (pnd) 3, to: (i) repeated-MS in home-environment (HOME-SEP), 8h-MS daily for three days with the pups remaining together in the home-cage; (ii) repeated-MS in a novel-environment (NOVEL-SEP), with the same separation procedure, but now the pups were individually housed in a novel-environment during the 8h dam's absence; (iii) repeated handling, which consisted of daily brief (15 min instead of 8h) MS in the home-altogether or in a novel-environment individually (HOME-HAN and NOVEL-HAN, respectively); (iv) no-separation/no-handling (NON-SEP/NON-HAN) control condition, in which pups were left undisturbed in their home-cage.
View Article and Find Full Text PDFDexamethasone (DEX), a synthetic glucocorticoid, has been used to treat respiratory distress syndrome in prematurely born infants. Despite the important short-term benefit on lung function, there is growing concern about the long-term outcome of this treatment, since follow-up studies of prematurely born infants have shown lasting adverse neurodevelopmental effects. Since the mechanism underlying these neurodevelopmental impairments is largely unknown, the aim of the present study was (i) to investigate the acute effects of neonatal DEX treatment on the developing brain; and (ii) to block specifically the effects of DEX on the brain by central administration of the glucocorticoid receptor (GR) antagonist mifepristone.
View Article and Find Full Text PDFBackground: In the present study, we tested both the cumulative stress and the mismatch hypothesis of psychopathology. For this purpose the combined effects of early-life adversity and later-life stress exposure on behavioral markers of psychosis susceptibility were studied in male Wistar rats.
Method: Experiment I: rat pups divided on the basis of the levels of their maternal care experience in low, medium or high maternal care groups, were reared post-weaning in groups (Exp.
The zebrafish is a powerful whole animal model which is complementary to in vitro and mammalian models. It has been shown to be applicable to the high-throughput behavioral screening of compound libraries. We have analysed 60 water-soluble toxic compounds covering a range of common drugs, toxins and chemicals, and representing various pharmacological mechanisms.
View Article and Find Full Text PDFBirth Defects Res C Embryo Today
June 2011
Technological innovation has helped the zebrafish embryo gain ground as a disease model and an assay system for drug screening. Here, we review the use of zebrafish embryos and early larvae in applied biomedical research, using selected cases. We look at the use of zebrafish embryos as disease models, taking fetal alcohol syndrome and tuberculosis as examples.
View Article and Find Full Text PDFBackground: In humans, ethanol exposure during pregnancy causes a spectrum of developmental defects (fetal alcohol syndrome or FAS). Individuals vary in phenotypic expression. Zebrafish embryos develop FAS-like features after ethanol exposure.
View Article and Find Full Text PDFAdrenal corticosterone secretion of newborn mice rapidly desensitizes to repeated maternal absence. The present study investigated the effects of novelty exposure, maternal care and genotype on this phenomenon. Maternal separation (MS) took place on postnatal days (pnd) 3-5.
View Article and Find Full Text PDFThe light/dark preference test is commonly used to assess anxiety-like phenotypes and validate the pharmacological effects of neuroactive compounds. This test has been recently adapted for adult zebrafish but has not yet been characterized and pharmacologically validated for young juvenile zebrafish. In the present study, we provide a detailed description of the pattern of exploratory behaviours encountered in juvenile zebrafish when exposed to the light/dark preference test.
View Article and Find Full Text PDFRationale: Human epidemiology and animal studies have convincingly shown the long-lasting impact of early life experiences on the development of individual differences in stress responsiveness in later life. The interplay between genes and environment underlies this phenomenon.
Objectives: We provide an overview of studies investigating the impact of early life experiences on the development of individual differences in neuroendocrine stress responsiveness in adulthood and address (1) impact of environment on later stress phenotypes, (2) role of genetic factors in modulating the outcome of environment, and (3) role of nonshared environmental experience in the outcome of gene × environment interplays.
Prog Neuropsychopharmacol Biol Psychiatry
August 2011
The study of the causes and mechanisms underlying psychiatric disorders requires the use of non-human models for the test of scientific hypotheses as well as for use in pre-clinical drug screening and discovery. This review argues in favor of the use of zebrafish as a novel animal model to study the impact of early (stressful) experiences on the development of differential stress phenotypes in later life. This phenomenon is evolutionary conserved among several vertebrate species and has relevance to the etiology of psychiatric disorders.
View Article and Find Full Text PDFPhysiother Theory Pract
November 2010
The purpose of this case report is to describe the impact of an 11-week hippotherapy program on the gross motor functions of two children (respectively 28 and 37 months old) diagnosed with Down syndrome. Hippotherapy is a strategy that uses the horse's motion to stimulate and enhance muscle contraction and postural control. The children were assessed by the Gross Motor Function Measure (GMFM) and accelerometry.
View Article and Find Full Text PDFThe current study provides a detailed description of the pattern of exploratory behaviors encountered in adult zebrafish when exposed to a novel/unfamiliar environment using the light/dark box and open field tests. We also document the impact of an acute stressor (restraint stress) given just prior the onset of behavioral testing. We report the following main findings: (1) zebrafish display anxiety-like behaviors including dark-avoidance (in light/dark box test) and thigmotaxis (in open field test), (2) upon exposure to a novel environment (first 2 min), zebrafish display place preference for the outer zone of the testing apparatus where they seek escape via the transparent wall, and exhibit high locomotor activity accompanied by high swimming speed, (3) thigmotaxis, behavioral hyperactivity, and swimming speed habituate (decrease) over time, (4) prior history of stress attenuates the natural tendency to engage in dark-avoidance behavior and thigmotaxis, reduces attempts to escape via the transparent wall, and greatly increased behavioral hyperactivity and swimming speed.
View Article and Find Full Text PDFBackground: The limbic system-associated membrane protein (LAMP) promotes development of neurons of limbic origin. We have previously shown that genetic deletion of LAMP results in heightened reactivity to novelty and reduced anxiety-like behaviors in mice. Here, we demonstrate a critical role of LAMP in hippocampal-dependent synaptic physiology and behavior.
View Article and Find Full Text PDFOne of the conundrums in today's stress research is why some individuals flourish and others perish under similar stressful conditions. It is recognized that this individual variability in adaptation to stress depends on the outcome of the interaction of genetic and cognitive/emotional inputs in which glucocorticoid hormones and receptors play a crucial role. Hence one approach towards understanding individual variation in stress coping is how glucocorticoid actions can change from protective to harmful.
View Article and Find Full Text PDFBasic research in pattern formation is concerned with the generation of phenotypes and tissues. It can therefore lead to new tools for medical research. These include phenotypic screening assays, applications in tissue engineering, as well as general advances in biomedical knowledge.
View Article and Find Full Text PDFMaternal licking and grooming (LG) exerts profound influence on hippocampal development and function in the offspring. However, little information is available on the effects of variations in maternal care on other brain regions. Here we examined the effects of variation in the frequency of maternal LG on morphological and electrophysiological properties of layer 2/3 pyramidal neurons in the somatosensory cortex in adult offspring.
View Article and Find Full Text PDFMaternal care in the rat influences hippocampal development, synaptic plasticity and cognition. Previous studies, however, have examined animals under minimally stressful conditions. Here we tested the hypothesis that maternal care influences hippocampal function differently when this structure is exposed to corticosteroid and noradrenergic hormones, which are elevated during the early phase of a stress response.
View Article and Find Full Text PDFGlucocorticoids (GCs) exert profound effects on a variety of physiological processes, including adaptation to stress, metabolism, immunity, and neuronal development. Cellular responsiveness to GCs depends on numerous factors, including the amount of the glucocorticoid receptor (GR) protein. We tested the hypothesis that micro-RNAs (miRs), a recently discovered group of noncoding RNAs involved in mRNA translation, might control GR activity by reducing GR protein levels in neuronal tissues.
View Article and Find Full Text PDFSemin Fetal Neonatal Med
June 2009
In this review, studies on the role of glucocorticoids during brain development are recapitulated with reference to their immediate effects and long-term impact on central functions. Traditionally, this research has focused on detrimental consequences of stress and exogenous glucocorticoid exposure but far less on the ability to develop resilience to stress despite exposure to early adversity. Recent findings suggest that the impact of early life conditions turns out as either harmful or protective depending on later environmental context.
View Article and Find Full Text PDFMaternal licking and grooming (LG) in infancy influences stress responsiveness and cognitive performance in the offspring. We examined the effects of variation in the frequency of pup LG on morphological, electrophysiological, and behavioral aspects of hippocampal synaptic plasticity under basal and stress-like conditions. We found shorter dendritic branch length and lower spine density in CA1 cells from the adult offspring of low compared with high LG offspring.
View Article and Find Full Text PDFIn humans, two glucocorticoid receptor (GR) splice variants exist: GRalpha and GRbeta, which are identical between amino acids 1-727 and then diverge. Whereas GRalpha (the canonical GR) acts as a ligand-activated transcription factor, GRbeta does not bind traditional glucocorticoid agonists, lacks GRalpha's transactivational activity, and acts as a dominant-negative inhibitor of GRalpha. It has been suggested that this receptor isoform is involved in the induction of glucocorticoid resistance in asthma patients.
View Article and Find Full Text PDFLipoprotein lipase (LPL) is a member of a lipase family known to hydrolyze triglyceride molecules found in lipoprotein particles. This particular lipase also has a role in the binding of lipoprotein particles to different cell-surface receptors. LPL has been identified in the brain but has no specific function yet.
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