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Biomedical subjects

M Reite

Publications and source records attributed to M Reite.

15 recordsLinked to original sources

Nocturnal sleep in separated monkey infants.

Nocturnal sleep was recorded from ten unrestrained, group-living Macaca nemestrina (pigtail) monkey infants, using implantable multichannel biotelemetry systems, during the agitation-depression behavioral reaction that follows maternal separation. Sleep disturbances during the four nights of separation were characterized by decreases in rapid eye movement (REM) time and in the number of REM periods, and increases in REM latency. Time awake and number of arousals were increased. Slow-wave sleep was not significantly affected. Sleep pattern changes were most pronounced the first separation night, and tended to decrease as separation continued, whereas behavioral measures of depression tended to increase as separation continued (up to four days). Sleep patterns returned to normal following reunion with the mother. Those infants who had the most severe sleep disturbances the first separation night (more time awake, less total sleep, less REM) also tended to become most depressed behaviorally later in the separation period.

Animals

Physiological correlates of maternal separation in surrogate-reared infants: a study in altered attachment bonds.

Three pigtail infant monkeys (Macaca nemestrina) were separated from their mothers shortly after birth and raised in social isolation on cloth surrogates. At about 24 weeks of age they were surgically implanted with multichannel biotelemetry systems. Following the collection of baseline behavioral and physiological data, the cloth surrogates were removed for 4 days, then returned. The behavioral and physiological (heart rate, body temperature, sleep patterns) reaction to separation from the surrogate was much less intense than is the case in group-living pigtail infants that are separated from their mothers, suggesting that the attachment bond to a cloth surrogate may be different than the bond to a living mother in a social group. Heart rate mean values and variability were similar in surrogate-reared and mother-reared infants, suggesting a degree of environmental independence in heart rate regulation.

Animals

Human magnetic auditory evoked fields.

Magnetoencephalographic (MEG) averaged auditory evoked fields to click stimuli (N = 512) were recorded from four human subjects. The MEG was recorded with an asymmetric second derivative SQUID gradiometer located in an aluminum shielded room. Unlike conventional EEG auditory evoked potentials, which have a widespread distribution, evoked magnetic fields appear to be localized to the general area of the primary auditory cortex and diminish rapidly in amplitude as the gradiometer is moved away in any direction.

Acoustic Stimulation

Heart rate and body temperature in separated monkey infants.

Heart rate (HR) and body temperature (BT) were recorded from ten unrestrained group-living M. nemestrina (pigtail) monkey infants, using totally implantable multichannel biotelemetry systems, during a 4-day base line (preseparation) period, during the agitation-depression reaction accompanying 4 days of maternal separation, and for several days following reunion with the mother. Quantified behavioral data were collected in nine of the ten infants. Mean daytime (1000 to 1600 hr) and nightime (2200 to 0400 hr) HR and BT values were computed for each infant, and for the group as a whole. The behavioral agitation reaction immediately following separation was accompanied by increases in both HR and BT. Beginning with the first night of separation, both HR and BT showed marked decreases from base line. Whereas group mean HR and BT changes were maximal early in the separation, behavioral indices of depression tended to be maximal later in the separation period. Reunion with the mother tended to normalize HR and BT in most infants. Two infants exhibited sudden transient reversible drops in nocturnal BT well into the separation period, suggesting an impairment in thermoregulatory mechanisms during the period of depressive behavior. One infant had a prolonged separation-induced decrease in HR that persisted throughout reunion, indicating that the stress of maternal separation may induce physiological changes that considerably exceed the duration of the effective stress.

Animals

Nocturnal sleep in isolation-reared monkeys: evidence for enviromental independence.

Thirteen all-night recordings were obtained from 3 infant pigtailed (Macaca nemestrina) monkeys raised on a cloth surrogate mother and under conditions of social isolation. Totally implantable biotelemetry systems were used to record the sleep physiology from the unrestrained animals. Sleep stages and night-to-night variability were virtually identical to values previously found in 8 mother-reared group-living infants. Sustained alterations in the early rearing enviroment, even though considerably modifying the organism's development, did not appear to result in differences in sleep organization.

Animals

The human magnetoencephalogram: some EEG and related correlations.

Simultaneous magnetoencephalographic (MEG) and electroencephalographic (EEG) data were recorded from six normal adult subjects. MEG signal strength and EEG voltage level appear to be linearly correlated. Spectral analysis suggested that the MEG and EEG data were produced by similar but non-identical generator systems. A vertex region magnetic averaged evoked response to flash was recorded in one (of four) subjects, consisting of a waveform similar to but out of phase with the simultaneous EEG averaged evoked response, such that cortical negativity was correlated with a magnetic field directed into the scalp. Eye movement artifact, which can seriously compromise EEG recordings, does not appear to be a major problem in MEG recordings.

Alpha Rhythm

Sleep physiology at high altitude.

All night sleep EEG, EKG, and respiration were recorded from six young men during 2 nights at sea level and 4 nonconsecutive nights at high altitude (14.110 ft., 4301 m). Sleep at high altitude was chraacterized initially by a significant decrease in Stages 3 and 4, a significant increase in the number of arousals, and a trend towards more time spent awake. In terms of actual time spent sleep, however, a relatively good night's sleep was obtained, which suggests that the objective sleep disturbance was not commensurate with the marked subjective complaints of sleeplessness. Periodic respiration during sleep was frequent at high altitude, was quickly terminated by oxygen administration, was not clearly related to the increased number of arousals, and usually was not seen during REM periods. Heart rate was increased during sleep at high altitude. All measures tended to return towards sea level means during 12 days at altitude. We suggest that the marked increase in the number of arousals may account for the disparity between the subjective reports and objective measures of sleep disturbance at high altitude. Although the objective sleep disruption is probably related in some fashion to hypoxemia, it is unclear whether hypoxemia itself or the alkalosis commonly present shortly after arrival at altitude is the major factor.

Adult