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Biomedical subjects

C Granier-Deferre

Publications and source records attributed to C Granier-Deferre.

13 recordsLinked to original sources
PubMed2004

Maturation of fetal responses to music.

Maturation of fetal response to music was characterized over the last trimester of pregnancy using a 5-minute piano recording of Brahms' Lullaby, played at an average of 95, 100, 105 or 110 dB (A). Within 30 seconds of the onset of the music, the youngest fetuses (28-32 weeks GA) showed a heart rate increase limited to the two highest dB levels; over gestation, the threshold level decreased and a response shift from acceleration to deceleration was observed for the lower dB levels, indicating attention to the stimulus. Over 5 minutes of music, fetuses older than 33 weeks GA showed a sustained increase in heart rate; body movement changes occurred at 35 weeks GA. These findings suggest a change in processing of complex sounds at around 33 weeks GA, with responding limited to the acoustic properties of the signal in younger fetuses but attention playing a role in older fetuses.

Acoustics↗
PubMed1992

Decelerative cardiac responsiveness to acoustical stimulation in the near term fetus.

Human fetal cardiac responses (36-39 weeks gestational age) to brief, repeated vocal stimuli (male or female voice uttering the same sentence), given at 90-95 dB SPL ex utero (around 20-30 dB less in utero) during a state of low fetal heart rate (FHR) variability, were examined using highly conservative statistical criteria taking into account each subject's prestimulus FHR variability. Subjects exposed to either of the two stimuli displayed significantly more decelerative heart rate (HR) changes compared to control subjects receiving no stimulation. The decelerative changes started during the first seconds following the onset of stimulation and reached their amplitude peak within 10 or 20 sec, depending on the subject. The direction--HR acceleration or deceleration--and the amplitude of the response depended on prestimulus HR variability only, not on prestimulus level. No major difference was found between the effects of the two voices. The data are compared to previous studies demonstrating fetal decelerative changes to acoustic stimuli of less than 105 dB SPL. The choice of an objective criterion to define an HR response and the possible orienting response nature of the decelerative change are discussed.

Arousal↗
PubMed1992

Fetal audition.

Explore the source record for details and available documents.

Acoustic Stimulation↗
PubMed1991

[Nasal chemoreception in utero: preliminary experiences in fetal sheep].

Intranasal injections of a fragrant solution of 2-methyl-2-thiazoline elicited significant heart rate decelerations in late pregnancy fetal sheep, while the injection of a control fluid (isotonic saline) had no effect. This result indicates that the ovine fetuses are able to detect nasally administered odorants, as previously demonstrated in the fetuses of murine rodents.

Administration, Intranasal↗
PubMed1988

Fetal cardiac and motor responses to octave-band noises as a function of central frequency, intensity and heart rate variability.

Accelerative and decelerative cardiac responses and motor responses (leg movements) of 37-40 weeks (G.A.) fetuses are analyzed as a function of the frequency of three octave-band noises (respectively centered at 500 Hz, 2000 Hz and 5000 Hz) and of their intensity level (100, 105, 110 dB SPL, ex utero), during high (HV) and low (LV) heart rate (HR) variability pattern states. In both states, increasing the frequency and/or the intensity of the acoustic stimulation: (i) increases the ratios and amplitudes of accelerations, and the motor response ratios, (ii) reduces deceleration ratios and motor response latencies. Cardiac and motor reactiveness are higher in HV than in LV with acceleration ratios always greater than motor ones. However, when a high intensity and/or frequency is used, the reactiveness differences between states disappears. Low intensity and/or frequency stimulation levels induce a majority of decelerations.

Acoustic Stimulation↗
PubMed1987

Deoxyglucose demonstration of in-utero hearing in the guinea pig foetus.

2-Deoxyglucose (2-[14C]DG) autoradiography was used to demonstrate central auditory function in the foetal guinea pig in-utero. The major advantage of this approach is that the experiment is carried out with the foetuses within the intact amniotic sac. Using pure tone stimuli at around 100 dB SPL, isofrequency bands of elevated metabolic activity were observed in the inferior colliculus of the majority of foetuses within the last 10 days of gestation.

Acoustic Stimulation↗
PubMed1987

[Fetal perception and discrimination of speech stimuli; demonstration by cardiac reactivity; preliminary results].

Human fetuses (35-38 ws GA), exposed to a repeated pair of syllables, either [ba] [bi] or [bi] [ba], at 95 dB SPL when in a low heart rate variability state, display a significant heart rate deceleration. Changing the order of the syllables in the pair, [ba] [bi] becoming [bi] [ba] (or the reverse), induces a new cardiac deceleration. This suggests that fetuses demonstrate auditory discrimination abilities for speech units like syllables.

Female↗
PubMed1986

Fetal responses to acoustic stimulation depend on heart rate variability pattern, stimulus intensity and repetition.

Fetuses (37-40 wks DA) were exposed to three successive presentations of a 5-s high-pass filtered (800 Hz) pink noise either at 105 dB or at 110 dB SPL. Stimulations were given during high or low variability heart rate (HR) patterns (HV or LV) which presumably correspond mostly to active and quiet sleep episodes, respectively. The proportion of fetuses showing cardiac response (CR) was always greater than the proportion showing leg movement (LM) but the presence of an accompanying leg movement always increased the amplitude of CR, independent of HR pattern, stimulus repetition and intensity. Fetal reactiveness always diminished with stimulus repetition but diminished more on the three examined dimensions (CR ratio, LM ratio and CR amplitude) with LV infants than with HV infants, and more with the 105 dB stimulus than with the 110 dB stimulus. More importantly, stimulus parameters and HR patterns interacted. At 110 dB in HV, neither the median amplitude of the CRs nor the probability of a CR changed over trials but the probability of a concommittant LM decreased. At 110 dB in LV, repetition induced a decrement on all three response dimensions from the second trial onwards. At 105 dB in HV, LM decreased rapidly, as much as at 110 dB in LV. Thus, state, as reflected by HR pattern, plays a significant role in determining the occurrence and the amplitude of the CR and the occurrence of a LM which, in turn, will enhance the CR amplitude.

Acoustic Stimulation↗
PubMed1986

[In utero demonstration of the functional activity of the auditory system of the fetus of guinea pigs by 14C 2-deoxyglucose autoradiography].

Pregnant guinea pigs injected with 2-DG between 10 to 2 days before birth, were exposed to loud free field pure tones (nine frequencies tested from 0.8 to 20 kHz). Specific bands of labeling were observed in the Inferior Colliculi of most of the fetuses whatever the frequency tested. The location of these isofrequency laminae shifted with stimulus frequency, their orientation were similar to those observed in the mothers. No such bands were found either in the control females or their fetuses. These results demonstrate that the auditory system of the fetus responds to frequencies up to 20 kHz, exhibits frequency selectivity and tonotopic organization in utero.

Animals↗
PubMed1985

Feasibility of prenatal hearing test.

Variability in foetal responses to sound stimulations is described and the effect of the different factors involved in this reactivity, in particular the physical characteristics of the stimulus and state of alertness of the foetus, is discussed. Results obtained with a high pass filtered pink noise at a 106, 109 and 113 dB SPL on 37-40 week foetuses are given to illustrate this dependency. For all tested levels, responsiveness was reduced after repetition of the stimulus. This was observed even at 113 dB when stimulation was preceded by a series of lower level stimuli to which foetuses were (or became) unresponsive. Motor responses (lower limb movements) were the first and the most affected by stimulus repetition, followed by cardiac response decrement--but with a lower proportion of non-responses, especially at 113 dB. Consequently, with this specific stimulus, cardiac reactivity seems a more reliable parameter to examine when more than one stimulus is needed to ascertain foetal hearing. It was also demonstrated that foetuses were much less reactive when stimulated during low heart rate variability sequences than during high heart rate variability. Testing of prenatal hearing seems feasible in utero and should be a promising method for detecting gross hearing impairment once the influence of each biophysical parameter has been carefully studied.

Female↗
PubMed1983

[Acoustic stimulation and adaptation to noise of the developing mouse auditory system].

To assess the effects of an acoustically enriched environment during the auditory system development, groups of mouse pups, from two strains (Swiss Albinos Rb-3 and deafness, the latter carrying a recessive gene [dn] making homozygous dn/dn totally deaf), were exposed to pulsed pure-tone stimulation (2 500 Hz; 85 +/- 5 dB SPL) at different periods of development from conception to weaning. Growth curve, weight at 40 days, eye opening and behaviour at 24 days to the same stimulus were analyzed as a function of the mother's audition (hearing or deaf) and of the period of acoustic exposure: exposed since conception, since birth or from 9 days (date of onset of audition). Eye opening is more precocious in all three experimental groups than in controls. Contrary to mouse pups exposed from 9 days, those (also from deaf mothers) treated before onset of hearing show normal growth and behavioural indifference to the stimulus at 24 days. The significant lack of physiological and behavioural effect of the sound stimulus in the groups treated before electrophysiological maturation of hearing has a certain lasting effect, at least up to age 40 days. As electrophysiological studies show no alteration of auditory thresholds in these groups, the hypothesis of a possible process of habituation, stemming from a very early effect of sound stimulation during the non-functional phase of development of the auditory system (from birth to 9 days), is discussed.

Acoustic Stimulation↗