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Biomedical subjects

H Thierry

Publications and source records attributed to H Thierry.

11 recordsLinked to original sources
PubMed1985

Ultradian and circadian respiratory rhythms in grouped small laboratory vertebrate species as a method to assess the effects of environmental challenges.

The recording over several days of the respiratory gases of groups of different laboratory vertebrates (mice, rats, quails), placed in a chamber with controlled ventilation, and in standardized environmental conditions of temperature, humidity, light, noise and feeding, shows ultradian (tau less than 24 hr) and circadian (tau congruent to 24 hr) rhythms. A simple variance analysis method shows periodic carbon dioxide changes, due to different environmental stimuli. Societal, light, acoustical, carbon monoxide and starvation challenges are given as examples. This technique enables us quickly to collect, on a great number of animals, data which correspond to societal behavior changes peculiar to the considered species.

Acoustic Stimulation↗
PubMed1984

Respiratory behavior in groups of deaf and non-deaf GFF male mice.

Carbon dioxide emission (VCO2) of groups of 10 GFF mice, genetically deaf and non-deaf, were compared, in controlled conditions of temperature 20-21 degrees C, humidity 50-80% and light (LD12:12; L = 108 lux). A circadian rhythm of VCO2 was evidenced in both genotypes, with levels in D and in L significantly (0.001 less than p less than 0.01) greater in deaf than in non-deaf mice. Photic VCO2 variations were significantly (0.001 less than p less than 0.05) smaller at L----D and D----L in the deaf than in non-deaf genotype. Ultradian (tau greater than 20 minutes) rhythms were evidenced in both genotypes; Fourier periodic analysis showed several significant (0.001 less than p less than 0.05) differences between these 2 genotypes concerning mainly amplitudes, whilst spectral analysis showed slight frequency differences between them. Survival to an acute nitrogen hypoxia or to an acute carbon monoxide intoxication which was significantly (p less than 0.001 and p less than 0.05) lower in deaf than in non-deaf individuals confirms the differences in respiratory behavior of groups of these two strains of mice.

Acoustic Stimulation↗
PubMed1983

Harmonic analysis of ultradian respiratory rhythms in four small laboratory vertebrates lit in LD12:12.

Fourier harmonic analysis has been applied to 20-min samples of VCO2, recorded every 12 sec over several (7-12) days, in one mouse, one rat, one guinea-pig, or one quail, maintained in controlled conditions of temperature, humidity and ventilation, and lit in LD12:12 (100 lux). The harmonic computations, during L and D of ultradian periods (1.2 hr less than tau less than 12 hr) evidence statistically significant differences in amplitude and phase between these four small laboratory species. These periodic respiratory differences correspond to discrepancies in their diurnal and nocturnal activities, and in their responses to light and dark.

Animals↗
PubMed1983

Inter and intraspecies genetic differences in survival to an acute carbon monoxide challenge in mice, rats, guinea-pigs, quails and chickens.

1. Groups of small laboratory vertebrates, of both sexes, have been submitted to an acute carbon monoxide challenge, close to a LD50. 2. An interspecific classification, from low to high CO sensitivity, gives: guinea-pigs-mice-chicks-rats-quails. 3. Interstrain statistical differences were observed in all species, with the exception of guinea-pigs. Furthermore, among two selected genotypes of Japanese quails, one was resistant to acute nitrogen hypoxia and to carbon monoxide intoxication and the other sensitive to both these types of hypoxia. 4. Interspecific comparisons show similarities of genetic differences to acute CO intoxication and acute nitrogen normobaric hypoxia.

Animals↗
PubMed1983

Environmental parameters in the experimental evaluation of a respiratory aggression.

Acute nitrogen normobaric hypoxic challenges, resulting in an approximately 50% overall survival, were performed in young adult male and female heterozygous OF1 mice under various environmental conditions. The time required to obtain 50% survival was 20 min for a constant pO2 of 42 Torr, and 151 min when pO2 was progressively lowered by nitrogen flushing from 159 to 16.5 Torr. In LD12:12 synchronized animals, survival was significantly (P less than 0.001) less when hypoxia was performed during the light (L) than during the dark (D) phase. Lowering the ambient temperature from 33.8 to 13.2 degrees C increased the length of the progressive hypoxia necessary to obtain a 50% survival of the mice by 1.7 times, and diminished the final pO2 from 35 to 12 Torr. Grouping and crowding both decreased hypoxic survival. A previous stress (starvation) diminished hypoxic resistance of mice, while a preceding hypoxia, carbon monoxide inhalation, or sodium cyanide injection had the opposite effect. In all instances, OF1 females were more resistant than males. Most of these variations can be related to differences in respiratory exchanges, locomotor activity and aggressiveness, which are dependent upon the various experimental environmental parameters.

Animals↗
PubMed1983

Evidence of genetic differences in acute hypoxia survival.

In a population of Japanese quail, a genetic selection was performed leading to two strains--one resistant and one susceptible to an acute hypoxic nitrogen challenge as well as to an acute carbon monoxide intoxication. Crossing these two strains gives an F1 hybrid whose survival to acute hypoxia appears to be very close to the susceptible strain. The difference in acute hypoxic survival already appears in embryos at the age of 12 d. Susceptibility to acute hypoxia seems to be a dominant character.

Animals↗
PubMed1982

Aging and intraspecific interactions in acute hypoxic survival of specific pathogen free OF1 mice of both sexes.

In light-synchronized pathogen-free OF1 mice, and LD50 acute hypoxic challenge was performed during the light period in which respiratory and motor activities are minimal. In males and females acute hypoxic resistance decreases with age. Grouping by ten significantly decreases hypoxic survival in young, adult, and senescent males, and in young females. In young mice, hypoxic survival is significantly less in males than in females, whether or not they have interindividual contacts. This sex-related difference disappears with aging in separated individuals, but remains in 230- and 420-day-old mice when there are interindividual contacts.

Aggression↗
PubMedDate not supplied

Respiratory activity variations induced in groups of LD 12:12 synchronized Sprague-Dawley rats by a 100 dB white noise emitted at 12-h intervals.

A white noise is emitted during 2 h, either in the middle of the scotoperiod (activity period) or of the photoperiod (rest period), on grouped specific pathogen free (SPF) male Sprague-Dawley rats, LD 12:12 synchronized by light (L = 6 h = 150 lux). Continuous measurements of VCO2, taken as an index of respiratory activity shows: 1. a short increase both after the beginning and the end of the stimulus, with slight time length differences between young and older rats; 2. a slight (2-3%) continued increase during the photoperiod and a high decrease (13%) during the scotoperiod. These VCO2 variations obtained during and after the white noise emission correspond to measurements of activity displacement and observations of behavior performed on a small sample of rats.

Age Factors↗