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Eye Opening (eye + opening)
Selected AbstractsThe "smellscape" of mother's breast: Effects of odor masking and selective unmasking on neonatal arousal, oral, and visual responsesDEVELOPMENTAL PSYCHOBIOLOGY, Issue 2 2007Sébastien Doucet Abstract Lactating women emit odor cues that release activity in newborns. Such cues may be carried in various substrates, including milk or areolar secretions. The present study aimed to examine the responses of infants facing their mother's breast and to sort out the source(s) of active volatile compounds emitted by the lactating breast. Infants (aged 3,4 days) were presented their mother's breast in two consecutive trials of 90 s each: a scentless condition (breast entirely covered with a transparent film) paired with one of four odorous conditions (fully exposed breast: n,=,15; nipple only exposed: 15; areola only exposed: 13; and milk exposed: 12). The infants were more orally activated when facing any of the odorous breast conditions than when facing the scentless breast. They cried earlier and longer, and opened their eyes less, when facing the scentless breast. Nipple, Areola, and Milk odors appeared to be equivalent to the whole breast odor in stimulating oral activity and in delaying crying onset. This study shows that volatile compounds originating in areolar secretions or milk release mouthing, stimulate eye opening, and delay and reduce crying in newborns. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 129,138, 2007. [source] Dark-rearing-induced reduction of GABA and GAD and prevention of the effect by BDNF in the mouse retinaEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2006Eun-Jin Lee Abstract Gamma-aminobutyric acid (GABA) is an important retinal neurotransmitter. We studied the expression of GABA, glutamate decarboxylase 65 (GAD65) and GAD67 by immunocytochemistry and Western blot, in the retinas of control and dark-reared C57BL/6J black mice. This study asked three questions. First, is visual input necessary for the normal expression of GABA, GAD65 and GAD67? Second, can the retina recover from the effects of dark-rearing if returned to a normal light,dark cycle? Third, does BDNF prevent the influence of dark-rearing on the expression of GABA and GAD? At postnatal day 10 (P10), before eye opening, GABA immunoreactivity was present in the ganglion cell layer (GCL), in the innermost rows of the inner nuclear layer (INL) and throughout the inner plexiform layer (IPL) of control and dark-reared retinas. In P30 control retinas, GABA immunoreactivity showed similar patterns to those at P10. However, in P30 dark-reared retinas, the density of GABA-immunoreactive cells was lower in both the INL and GCL than in control retinas. In addition, visual deprivation retarded GABA immunoreactivity in the IPL. Western blot analysis showed corresponding differences in the levels of GAD65 but not of GAD67 expression between control and dark-rearing conditions. In our study, dark-rearing effects were reversed when the mice were put in normal cyclic light,dark conditions for 2 weeks. Moreover, dark-reared retinas treated with BDNF showed normal expression of both GABA and GAD65. Our data indicate that normal expression of GABA and GAD65 is dependent on visual input. Furthermore, the data suggest that BDNF controls this dependence. [source] Minocycline attenuates hypoxia,ischemia-induced neurological dysfunction and brain injury in the juvenile ratEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2006Lir-Wan Fan Abstract To investigate whether minocycline provides long-lasting protection against neonatal hypoxia,ischemia-induced brain injury and neurobehavioral deficits, minocycline was administered intraperitoneally in postnatal day 4 Sprague,Dawley rats subjected to bilateral carotid artery occlusion followed by exposure to hypoxia (8% oxygen for 15 min). Brain injury and myelination were examined on postnatal day 21 (P21) and tests for neurobehavioral toxicity were performed from P3 to P21. Hypoxic,ischemic insults resulted in severe white matter injury, enlarged ventricles, deficits in the hippocampus, reduction in numbers of mature oligodendrocytes and tyrosine hydroxylase-positive neurons, damage to axons and dendrites, and impaired myelination, as indicated by the decrease in myelin basic protein immunostaining in the P21 rat brain. Hypoxic,ischemic insult also significantly affected physical development (body weight gain and eye opening) and neurobehavioral performance, including sensorimotor and locomotor function, anxiety and cognitive ability in the P21 rat. Treatments with minocycline significantly attenuated the hypoxia,ischemia-induced brain injury and improved neurobehavioral performance. The protection of minocycline was associated with its ability to reduce microglial activation. The present results show that minocycline has long-lasting protective effects in the neonatal rat brain in terms of both hypoxia,ischemia-induced brain injury and the associated neurological dysfunction. [source] In vivo optical recordings of synaptic transmission and intracellular Ca2+ and Cl, in the superior colliculus of fetal ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2006Yoshiyuki Sakata Abstract Although the N -methyl- d -aspartate (NMDA) receptor is known to play a crucial role in activity-dependent remodeling of synaptic connections in the fetal superior colliculus (SC), its contribution to the electrical activity of fetal SC neurons has not been determined. Furthermore, whether ,-aminobutyric acid (GABA)-mediated inhibition occurs either as early as prenatal periods or only after eye opening has been controversial. We therefore performed optical recordings using voltage-, Ca2+ - and Cl, -sensitive fluorescent dyes to analyse synaptic transmission and changes in intracellular Ca2+ and Cl, in the SC of fetal rats that were still connected with the dams by the umbilical cord. Excitatory and inhibitory responses were evoked by focal SC stimulation. The excitatory synaptic responses are composed of early and late components. The early component was mediated by both non-NMDA and NMDA receptors, whereas the late component occurred mainly via NMDA receptors. Train pulse stimulation at higher currents was required for induction of the inhibition, which was antagonized by bicuculline, and blocking of the GABA-mediated inhibition by bicuculline uncovered masked excitatory synaptic responses. Focal SC stimulation induced increases in [Cl,]i and [Ca2+]i that were mediated by GABA-A receptors and mainly by NMDA receptors, respectively. GABA antagonists augmented SC-induced increases in [Ca2+]i. These results indicate that, in the fetal SC, excitatory and inhibitory synaptic transmissions occur before birth, that the NMDA receptor is a major contributor to excitatory synaptic transmission and increased [Ca2+]i, and that the GABA-A receptor is already functioning to inhibit excitatory neurotransmission. [source] GluR- and TrkB-mediated maturation of GABAA receptor function during the period of eye openingEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2005Christian Henneberger Abstract Synapse maturation includes the shortening of postsynaptic currents, due to changes in the subunit composition of respective transmitter receptors. Patch clamp experiments revealed that GABAergic inhibitory postsynaptic currents (ISPCs) of superior colliculus neurons significantly shorten from postnatal day (P)1 to P21. The change started after P6 and was steepest between P12 and P15, i.e. around eye opening. It was accompanied by enhanced sensitivity to zolpidem and increased expression of GABAAR ,1 mRNA, whereas the level of ,3 mRNA decreased. This result is consistent with the hypothesis that the IPSC kinetics of developing collicular neurons is determined by the level of ,1/,3. As ,1/,3 peaked when N -methyl-D-aspartate receptor (NMDAR)-mediated synaptic currents reached their maximum (P12) it was asked whether NMDAR activity can shape the kinetics of GABAergic IPSCs. Cultured collicular neurons were treated with NMDA or NMDAR block, and it was found that the former resulted in faster and the latter in slower IPSC decay. Group I mGluR blockade had no effect. Experiments with bdnf,/, mice revealed that, with some delay, the increase of ,1/,3 mRNA also occurred in the chronic absence of brain-derived neurotrophic factor (BDNF) and, again, this was accompanied by the shortening of IPSCs. In addition, there was an age-dependent depression of IPSC amplitudes by endogenous BDNF, which might reflect the developmental increase in the expression of GABAAR ,2L, as opposed to ,2S. Together, these experiments suggest that the GABAAR , subunit switch and the associated change in the IPSC kinetics were specifically controlled by NMDAR activity and independent on the signalling through group I mGluRs or TrkB. [source] Neurobehavioral toxicity study of dibutyl phthalate on rats following in utero and lactational exposureJOURNAL OF APPLIED TOXICOLOGY, Issue 7 2009Yuanfeng Li Abstract To investigate the neurobehavioral effects of dibutyl phthalate (DBP), an important endocrine disruptor known for reproductive toxicity, on rodent offspring following in utero and lactational exposure, pregnant Wistar rats were treated with DBP (0, 0.037, 0.111, 0.333 and 1% in the diet) from gestation day (GD) 6 to postnatal day (PND) 28, and selected developmental and neurobehavioral parameters of the offspring were measured. There were no significant effects of DBP on body weight gain of the dams during GD 6,20 or on the pups' ages of pinna detachment, incisor eruption or eye opening. Exposure to 1% DBP prolonged gestation period, decreased body weight in both male and female pups, depressed surface righting (PND 7) in male pups, shortened forepaw grip time (PND 10), enhanced spatial learning and reference memory (PND 35) in male pups. Exposure to 0.037% DBP also shortened forepaw grip time (PND 10), but inhibited spatial learning and reference memory in male pups. Sex × treatment effects were found in forepaw grip time (PND 10), spatial learning and reference memory, and the male pups appeared to be more susceptible than the females. However, all levels of DBP exposure did not significantly alter surface righting (PND 4), air righting (PND 16), negative geotaxis (PND 4 or 7), cliff avoidance (PND 7) or open field behavior (PND 28) in either sex. Overall, the dose level of DBP in the present study produced a few adverse effects on the neurobehavioral parameters, and it may alter cognitive abilities of the male rodent. Copyright © 2009 John Wiley & Sons, Ltd. [source] Oro-facial activities in sleep bruxism patients and in normal subjects: a controlled polygraphic and audio,video studyJOURNAL OF ORAL REHABILITATION, Issue 2 2009K. M. C. DUTRA Summary, To our knowledge, the large spectrum of sleep motor activities (SMA) present in the head and neck region has not yet been systematically estimated in normal and sleep bruxism (SB) subjects. We hypothesized that in the absence of audio,video signal recordings, normal and SB subjects would present a high level of SMA that might confound the scoring specificity of SB. A retrospective analysis of several SMA, including oro-facial activities (OFA) and rhythmic masticatory muscle activities (RMMA), was made from polygraphic and audio,video recordings of 21 normal subjects and 25 SB patients. Sleep motor activities were scored, blind to subject status, from the second night of sleep recordings. Discrimination of OFA included the following types of activities: lip sucking, head movements, chewing-like movements, swallowing, head rubbing and scratching, eye opening and blinking. These were differentiated from RMMA and tooth grinding. The frequency of SMA per hour of sleep was lower in normal subjects in comparison with SB patients (P < 0·001). Up to 85% of all SMA in normal subjects were related to OFA while 30% of SMA in SB patients were related to OFA scoring (P < 0·001). The frequency of RMMA was seven times higher in SB patients than in normal subjects (P < 0·001). Several SMA can be observed in normal and SB subjects. In the absence of audio,video signal recordings, the discrimination of various types of OFA is difficult to achieve and may lead to erroneous estimation of SB-related activities. [source] Comparison of recovery properties of desflurane and sevoflurane according to gender differencesACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2005E. Tercan Background:, The aim of this study was to investigate the recovery properties of desflurane and sevoflurane in patients undergoing elective surgery, according to the gender differences. Methods:, In the study, 160 ASA class I,II patients aged between 20 and 60 years were included. The patients were assigned into two groups according to their gender, and these groups were randomly divided into two groups according to a selected volatile anaesthetic agent. Intraoperative bispectral index, time of postoperative achievement for end-tidal concentrations of volatile agents to decline 50% (ET-AA%50), time for extubation, time for eye opening and orientation, and time for bispectral index values to reach control values were recorded. Aldrete scores and error points of a delayed memory recall test were determined. Results:, Desflurane groups had a shorter ET-AA%50 time, extubation and eye-opening time in male and female patients compared to the sevoflurane groups, and these results were statistically significant (P < 0.05). In both the desflurane and sevoflurane groups, ET-AA%50 time, extubation and eye-opening time were shorter in male patients than in female patients, and these results were also statistically significant (P < 0.05). There were no significant differences among the groups in terms of Aldrete scores and error points of delayed memory recall test (P > 0.05). Conclusion:, In conclusion, early recovery time was shorter in male patients compared to female patients in both the desflurane and sevoflurane groups. Additionally, in the desflurane groups it was shorter in the sevoflurane groups for both genders. [source] Developmental shift from long-term depression to long-term potentiation in the rat medial vestibular nuclei: role of group I metabotropic glutamate receptorsTHE JOURNAL OF PHYSIOLOGY, Issue 2 2003Julien Puyal The effects of high frequency stimulation (HFS) of the primary vestibular afferents on synaptic transmission in the ventral part of the medial vestibular nuclei (vMVN) were studied during postnatal development and compared with the changes in the expression of the group I metabotropic glutamate receptor (mGluR) subtypes, mGluR1 and mGluR5. During the first stages of development, HFS always induced a mGluR5- and GABAA -dependent long-term depression (LTD) which did not require NMDA receptor and mGluR1 activation. The probability of inducing LTD decreased progressively throughout the development and it was zero at about the end of the second postnatal week. Conversely, long-term potentiation (LTP) appeared at the beginning of the second week and its occurrence increased to reach the adult value at the end of the third week. Of interest, the sudden change in the LTP frequency occurred at the time of eye opening, about the end of the second postnatal week. LTP depended on NMDA receptor and mGluR1 activation. In parallel with the modifications in synaptic plasticity, we observed that the expression patterns and localizations of mGluR5 and mGluR1 in the medial vestibular nuclei (MVN) changed during postnatal development. At the earlier stages the mGluR1 expression was minimal, then increased progressively. In contrast, mGluR5 expression was initially high, then decreased. While mGluR1 was exclusively localized in neuronal compartments and concentrated at the postsynaptic sites at all stages observed, mGluR5 was found mainly in neuronal compartments at immature stages, then preferentially in glial compartments at mature stages. These results provide the first evidence for a progressive change from LTD to LTP accompanied by a distinct maturation expression of mGluR1 and mGluR5 during the development of the MVN. [source] | |||||||||||||