Kornilova L.N.,Institute of Biomedical Problems IBMP |
Naumov I.A.,Institute of Biomedical Problems IBMP |
Glukhikh D.O.,Institute of Biomedical Problems IBMP |
Habarova E.V.,Institute of Biomedical Problems IBMP |
Kozlovskaya I.B.,Institute of Biomedical Problems IBMP
Human Physiology | Year: 2013
In order to determine the effects of support and proprioceptive afferentation on the characteristics of visual-manual tracking (VMT), we used a model of weightlessness-horizontal dry immersion. Altogether 30 subjects who stayed in the immersion bath from 5 to 7 days were examined to evaluate the accuracy of the VMT in tasks to pursue the jerky (saccadically) and smooth (linear, pendular and circular) movement of a point visual stimulus. Examinations were performed before, during and after immersion using electrooculography (to record eye movements) and a joystick (to record hand movements) with a biological visual feedback-one of the two visible stimuli on the screen matched the current angle of the joystick handle. Computerized visual stimulation programs were presented to subjects using virtual-reality glasses. We analyzed the time, amplitude and velocity characteristics of the visual and manual tracking (VT and MT respectively), including the efficiency ratio (eVT and eMT) and the gain (gVT and gMT) as the respective ratios of the amplitudes and velocities of the eyes/hand movements to the stimulus movement. eVT was significantly reduced in comparison to the baseline all the time, while the subject lay in the immersion bath and until R+4 day after immersion. eMT decreased significantly only on I-1 and I-3 days of immersion. gVT significantly differed from the baseline only on I-3 and I-6 days of immersion and R+1 day after immersion. We found no significant changes in gMT. Evaluations of the vestibular function (VF) were performed before and after immersion using videooculography. We analyzed the static torsional otolith-cervical-ocular reflex (OCOR), the dynamical vestibular-cervical-ocular reactions (VCOR), spontaneous eye movements (SpEM), and the accuracy of the perception of the subjective visual vertical (SVV). After immersion, 47% of all subjects had a significant reduction of OCOR with a simultaneous significant increase of VCOR on 37% of subjects, as well as significant changes in the accuracy of the perception of the SVV, which correlated with changes in OCOR. We found a correlation between characteristics of the VT and MT and between the characteristics of the VF and VT, but we found no correlation between VF and MT. We discovered that removal of the support and minimization of the proprioceptive afferentation has a greater impact upon the accuracy of the VT than the accuracy of the MT. © 2013 Pleiades Publishing, Inc.
PubMed | Ludwig Maximilians University of Munich, Max Von Pettenkofer Institute and Institute of Biomedical Problems IBMP
Type: | Journal: Scientific reports | Year: 2015
Environmental factors have long been known to influence immune responses. In particular, clinical studies about the association between migration and increased risk of atopy/asthma have provided important information on the role of migration associated large sets of environmental exposures in the development of allergic diseases. However, investigations about environmental effects on immune responses are mostly limited in candidate environmental exposures, such as air pollution. The influences of large sets of environmental exposures on immune responses are still largely unknown. A simulated 520-d Mars mission provided an opportunity to investigate this topic. Six healthy males lived in a closed habitat simulating a spacecraft for 520 days. When they exited their spacecraft after the mission, the scenario was similar to that of migration, involving exposure to a new set of environmental pollutants and allergens. We measured multiple immune parameters with blood samples at chosen time points after the mission. At the early adaptation stage, highly enhanced cytokine responses were observed upon ex vivo antigen stimulations. For cell population frequencies, we found the subjects displayed increased neutrophils. These results may presumably represent the immune changes occurred in healthy humans when migrating, indicating that large sets of environmental exposures may trigger aberrant immune activity.