Response of mother and infant squirrel monkeys to separation and disturbance

Plasma cortisol values were obtained from squirrel monkey mothers and infants after two types of brief separation: infant removed to a nearby cage and infant removed to a different room. Cortisol values were also obtained during basal conditions, and after 30 min exposure to an unfamiliar juvenile conspecific when mothers and infants were allowed to maintain contact. For either separation condition, both mothers and infants exhibited significant cortisol elevations, and overall, infants ‘corticoid values were much greater than mothers’. Behavioral measures were also obtained from mothers, who during both separations tended to show marked behavioral agitation. The partner's presence or absence during separation did not produce differential behavioral or corticoid responses by either mother or infant. However, the presence of the unfamiliar conspecific induced clearly significant cortisol elevations in the infant but only slight elevations in the mother.     

Social and environmental factors influencing mother-infant separation-reunion in squirrel monkeys

Sixteen squirrel monkey mother and infant dyads were housed in groups of two. They were separated and then immediately reunited in their familiar home cage or in a novel environment, either in conjunction with the second mother-infant dyad, or as a single manipulated pair. Behavioral observations of both dyads were made during the 30-min period following these manipulations; blood samples were then taken for cortisol assay. Mothers' locomotor activity increased when a single dyad was manipulated in the home cage and decreased in the novel environment where proximity between the pairs increased. Cortisol levels varied significantly across conditions, with mothers and infants responding to different stimuli. Mothers responded primarily to social disruption, including separation from the other dyad, and infants responded most clearly to novelty and separation from the other dyad. No significant differences were observed over base levels when both mother and infant pairs were reunited in the home cage, indicating that changes were not due to the disturbance involved in the separation procedure.     

Role of midbrain central gray in pain-induced defensive boxing of rats

Pain-induced defensive boxing behavior in the rat was impaired or abolished by lesions of the midbrain central gray at the level of the superior colliculus. Lesions which left part of this region intact along with its lateral and dorsal connections did not produce boxing deficits despite destruction of anterior, posterior, or ventral connections. On the basis of these data, consideration of the anatomy and physiology of the central gray, and comparison to data on affective defense in the cat, it was suggested that this region may function as a modal command system or a patterning mechanism independent of the forebrain for pain-induced defensive boxing in the rat and affective defense in the cat. The central gray was shown to be necessary for freezing and escape behaviors as well as pain-induced defensive boxing, which led to speculation about its role in committing the animal to one or another of these three alternative responses to pain or threat.     

The role of peers in modifying behavioral distress and pituitary-adrenal response to a novel environment in year-old rhesus monkeys

The effects of a peer's presence were examined for 9 mother-reared rhesus monkeys (mean age=12 months). Subjects were captured from their social groups and placed in single cages for 24 hr under each of 4 conditions: Alone, with Mother, with a Peer from the Same Group, or with a Peer from a Different Group. Plasma cortisol and behavioral data were obtained. Thirty min after capture the presence of a peer from a different social group produced elevations in plasma cortisol greater than those observed in all but the Alone condition. This effect was not apparent 24 hr later. Furthermore, by 22 hr after capture the presence of a peer from either social group significantly reduced agitated behavior, as compared to responses observed when subjects were housed alone. These subjects thus readily habituated to the less familiar peer to whom they initially responded. Physical contact and whoo calling clearly differentiated responses to peer from mother, suggesting that the calming effect of a peer's presence was not sufficient that the peer serve as a surrogate attachment figure. The results indicate the role of peer conspecifics in modifying responses to stressful situations in young group-reared rhesus monkeys.     

Failure of noise exposure to modify temporal patterns of plasma cortisol in man

Summary The purpose of this investigation was to assess the modification in the temporal pattern of plasma cortisol levels during exposure to noises of different intensities, frequencies and durations. Plasma cortisol concentrations were measured from 08.00 h to 15.00 h at 10 min intervals in eight subjects on a control day and one or two exposure days. Noise exposures induced no significant increase in plasma cortisol concentration. It is concluded that noise, at safe levels for human hearing conservation, when not associated with other potentially noxious stimuli does not cause hyperactivity of the pituitary-adrenocortical system. These results do not tally with those from animal studies where noise is known to activate corticotrophin (ACTH) secretion.     

Plasma adrenocorticotrophin and cortisol responses to acute hypoxia at rest and during exercise

Summary Plasma adrenocorticotrophin (ACTH) and cortisol (F) concentrations were studied in six male subjects under normoxic (N) and acute hypoxic (H) conditions (altitude 3000 m) in a hypobaric chamber. Comparisons were made at rest, at 15, 30, and 60 min of exercise (65% ), and after a 10 min recovery period. Mean (±SE) resting plasma ACTH levels were significantly higher in H (18.6±5.7 pmol · l^–1) than in N (9.6±1.6 pmol · l^–1) but no difference in resting plasma cortisol was observed between the two conditions. Both plasma ACTH and F concentrations were significantly increased at 60 min of exercise and during the recovery period under normoxic conditions. Hypoxia did not affect the ACTH response to exercise but reduced cortisol elevation. The changes in plasma cortisol concentration from rest to exercise were significantly correlated to ACTH under normoxic (r=0.89,p<0.001) but not under hypoxic (r=0.43, NS) conditions. Plasma lactate concentration was higher at the end of exercise in hypoxia (p<0.01), and no correlation existed between plasma lactate and ACTH levels. These observations provide further evidence that at sea level the increase in plasma cortisol levels during exercise is the result of ACTH-induced steroidogenesis. The responses observed at rest and during exercise in hypoxia suggest that adrenal sensitivity for ACTH may be altered.     

The measurement and study of maternally-directed activity in the developing rat

Procedures and methods are described for measuring the vigorous search behavior of developing rats on their anesthetized mothers, or other test stimuli. The apparatus yields three measures of maternally-directed activity: (1) vibrations, (2) time, and (3) active $\text{1}\text{2}$ sec intervals- in proximity. Deprived pups (8–9 days old) had higher vibrational levels than nondeprived pups, and they graded their activity responses into 5 different levels. The highest levels were obtained next to the ventrum of their natural mother, and only slightly lower levels were emitted toward the ventrum of lactating females with pups of comparable age. Activity was significantly lower next to the ventrum of a virgin female, and still lower levels were emitted next to the ventrum of a male rat or the dorsal surface of a lactating female. Deprivation effects were absent with these last two stimuli. The lowest activity levels were emitted toward a wooden block or plastic container. This apparatus yields a sensitive and discriminitive measure of maternally-directed activity, and provides information on the features of the mother involved in producing this response.     

High-fidelity evoked potential for mapping the rat tail in thalamus

The technique of field potentials (FPs) provides a macroscopic view for exploring brain function, and is supplementary to single-unit recording, a microscopic view that investigates each neuron in great detail. Mapping the rat tail in the ventroposterolateral (VPL) nucleus of the thalamus was carried out by analyzing the current source density (CSD) of the evoked FPs. The results showed a clear somatotopic organization of the tail in the VPL nucleus. Also, to obtain high-fidelity FPs, two recording parameters were determined. Based upon cross-correlation coefficient (rho), the cycles of FPs needed to be averaged should not be less than 50 and the distance between the two recording sites should be no longer than 50 mum in each direction (mediolateral, anteroposterior and ventrodorsal). Under these conditions, the representation (or reproducibility) of an FP can be >95%. The procedures used to determine these parameters can serve as a guide to obtain FPs with high signal-to-noise ratio and without spatial aliasing error.     

Sex differences in adrenocortical response to controlled agonistic encounters in rhesus monkeys

A paradigm for laboratory investigation of primate agonistic behaviors and hormonal correlates without the complication of physical trauma was investigated. The introduction of an individual rhesus monkey (Macaca mulatta) into a protected inner cubicle of an unfamiliar group's pen resulted in a patterned aggressive response, which was of greater intensity to male than female newcomers. All newcomers responded to introductions with elevations in plasma cortisol which were highly correlated with the level of aggression that had been directed toward them, but which were less easily predicted from observational measures of their own behavior during encounters. Basal plasma cortisol levels of females were higher, and their response elevations varied over a wider range than for males, suggesting that females may show a higher response ceiling to the stress received.     

Interrelations between age and plasma renin,aldosterone and cortisol,urinary catecholamines,and the body sodium/volume state in normal man

Summary Interrelations between age and plasma renin, aldosterone and cortisol levels, urinary catecholamines, plasma and blood volumes, exchangeable body sodium and blood pressure were studied in 28 young (19 to 29 years), 16 middle-aged (32 to 58 years) and 15 elderly (60 to 74 years) healthy subjects. Supine and upright plasma renin and supine aldosterone levels decreased while urinary noradrenaline excretion rate increased progressively with aging (r0.34;p<0.05), with significant differences in mean values between young and elderly subjects (p<0.02). There was also an age-related decrease in upright plasma aldosterone concentration, although this was not statistically significant. Furthermore, mean plasma cortisol concentrations increased in response to upright posture in elderly (+50%;p<0.02), but not in young (–10%) or middle-aged (–8%) subjects. Blood pressure correlated with age (r=0.35;p<0.05) or noradrenaline excretion rate (r=0.34) in the entire study population and with blood volume in the elderly (r=0.68), but not in the young or middle-aged study groups. There were no significant age-related differences in the body sodium/volume state, basal plasma cortisol levels or urinary adrenaline excretion rate, and plasma renin or aldosterone levels did not correlate with these parameters or with blood pressure. It is concluded that the influence of age on plasma renin or aldosterone levels, plasma cortisol responsiveness to upright posture, and urinary noradrenaline excretion should be taken into consideration, whenever these factors have to be interpreted in patients with arterial hypertension or other clinical disorders. Furthermore, these data are consistent with the possibility that in normal man increases in supine blood pressure with aging may be related at least partly to concomitant changes in free peripheral noradrenaline.This investigation was supported by the Swiss National Science Foundation     

通督调神针法对PSD患者COR的影响及临床研究

目的 通过通督调神针法对脑卒中后抑郁患者进行针刺治疗,观察血浆皮质醇水平的变化及临床疗效。方法 选取2015 年12 月~2016年11 月我院60例PSD患者,按数字随机法分为治疗组和对照组,每组30例。治疗组行通督调神针刺治疗,对照组行盐酸氟西汀胶囊药物治疗,治疗4周后,采用临床神经功能缺损程度评分表评定神经功能,汉密尔顿抑郁量表24项评定抑郁状态, BartheI指数评定日常活动能力,以及应用放射免疫法测定COR的含量浓度,观察两组对PSD患者治疗的疗效。结果 治疗组总有效率93.10%,对照组总有效率90.00%,两组对比差异无统计学意义（P＞0.05）;两组在NIHSS、HAMD、ADL量表的改善方面,治疗组评分改善情况优于对照组,差异有统计学意义（P＜0.05）;两组COR含量比较方面,两组差异无统计学意义（P＞0.05）。结论 通督调神针法治疗PSD可显著改善患者的临床症状和生活质量,值得临床上进一步深入研究。     

Nutritional variables and their effect on the development of ultrasonic vocalizations in rat pups

Measures of ultrasonic vocalizations were made on alternate days during the first and second weeks postpartum in rat pups reared by mothers fed either control (23%) or low protein (8%) diets. Compared to those reared by control mothers, pups reared by low protein mothers emitted significantly fewer ultrasonic vocalizations. The hypothesis that malnutrition might shift the age at which peak rate of vocalizations were emitted was not confirmed.     

The rat exposure test: a model of mouse defensive behaviors

In order to facilitate behavioral, and potentially pharmacological, analyses of risk assessment behaviors in mice, a rat exposure test (RET) was devised and evaluated. This test provides a home chamber connected via a tunnel to a rat (predator) exposure area. Familiar substrate is provided to permit burying, and mouse subjects are habituated to the apparatus prior to exposure to an amphetamine-activated rat. In comparison to toy-rat-exposed controls, rat-exposed BALB/c mice showed significantly more risk assessment [stretch attend posture (SAP) and stretch approach], freezing, and avoidance (time in the home chamber), and less time in contact with the wire mesh screen between itself and the threat stimulus. When BALB/c, C57BL/6, CD-1, and Swiss-Webster mice were compared in this test, the two inbred strains (BALB/c and C57BL/6) tended to show more extreme values of particular defensive behaviors, compared to the two outbred strains (Swiss-Webster and CD-1). C57BL/6 mice showed more avoidance and higher levels of SAP, freezing, and burying than BALB/c and more than one or both outbred strains as well. BALB/c mice showed little defensive burying, both in comparison to toy-exposed controls (Experiment 1), and in comparison to the three other strains in Experiment 2. These findings are somewhat at variance with characterizations of anxiety in C57BL/6 and BALB/c mice, based on tests utilizing novel areas and noxious stimuli, suggesting strain differences in defensiveness to such stimuli, compared to antipredator defense levels. Nonetheless, with the exception of burying in BALB/c mice, all strains showed all defensive behaviors measured to the rat stimulus. In particular, SAP levels were substantial in all strains tested, suggesting the usefulness of this test in assessment of the role of risk assessment in defense.     

Maternal care received by rat pups treated with 6-hydroxydopamine

Selective depletion on CNS dopamine in neonatal rats, by intracisternal injection of 6-hydroxydopamine on the fifth day of life, is associated with hyperactivity, learning disturbances, and growth retardation. To assess the degree to which pup behavioral deficits result from, or influence, alterations in maternal care, mother-pup interaction was investigated during the first 13 days of pup life in 3 groups of litters: 6-OHDA-treated, sham treated, and normal control. Measures of maternal behaviors included nursing, nest-building, retrieval, and locomotor activity; biological measures of pup maturation included weight, length, and righting time. These indices of mother-pup interaction revealed 4 stable dimensions and significant developmental patterns. 6-OHDA-treated pups were significantly lighter and shorter, and somewhat retarded in righting time. Although pup 6-OHDA treatment did not disrupt the organization or sequence of mothering, treated pups were increasingly distinguished from controls by the promptness with which they were retrieved. The profound and enduring behavioral deficits of dopamine depletion in the newborn period appear to occur in the presence of adequate, and perhaps enhanced, maternal care.     

The dexamethasone suppression test in depressive, non-depressive and schizoaffective psychosis

The authors examined the 24-h plasma cortisol response to dexamethasone in 19 patients with co-existing depressive and psychotic features and in 12 non-depressed patients with only psychotic features. The rate and degree of abnormal dexamethasone suppression was greatest in patients who met RDC criteria for primary depressive disorder. Patients who met criteria for schizoaffective--mainly schizophrenic--depressed and other psychotic disorders did not differ from each other in their response to dexamethasone. These data suggest that the DST may have utility in the diagnostic evaluation of some patients with depressive and psychotic features.     

Lack of GABAergic modulation of acetylcholine turnover in the rat thalamus

In order to investigate the GABAergic modulation of the cholinergic midbrain-thalamus pathway, the effects of the GABAA agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP) and of the benzodiazepine, diazepam, on acetylcholine (ACh) turnover in the thalamus have been studied. TRACh was also measured in the frontal and parietal cortices of the same animals. Our data confirm an inhibitory GABAergic modulation of the cholinergic nucleus basalis-cortex projection but suggest a lack of GABAergic modulation of the cholinergic midbrain-thalamus pathway.