Effects of escape to alone versus escape to enriched environments on adaptive and aberrant behavior.
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Escape-maintained aberrant behavior may be influenced by two outcomes: (a) a break from the activity and (b) subsequent access to preferred activities. To assess this hypothesis, a treatment was developed that analyzed response allocation across two break options: break alone and break with access to preferred social activities. The break with preferred activities decreased aberrant behavior and increased appropriate behavior. (+info)
The effect of progesterone alone or in combination with estradiol on follicular dynamics, gonadotropin profiles, and estrus in beef cows following calf isolation and restricted suckling.
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The effects of calf isolation and restricted suckling on LH pulse characteristics and interval to first ovulation (postpartum interval) were studied in 52 multiparous beef cows, with or without exogenous progesterone. At 30 d postpartum, cows were randomly allocated to one of four treatments (n = 13/treatment): 1) Ad lib, ad libitum access of cows to calves; 2) CI/RS, calf isolation/restricted suckling, where suckling was restricted to once daily; 3) CI/RS+P4, same as CI/RS but cows received an intravaginal progesterone-releasing device at calf isolation for 6 d; or 4) CI/RS+P4+E2, as CI/RS+P4 but the intravaginal progesterone-releasing device had a 10-mg estradiol capsule attached. Daily ovarian scanning and twice-daily blood sampling were performed from d 25 postpartum until the day of second ovulation. A random sample of cows from each treatment (n = 31 in total) were blood-sampled at 15-min intervals for 10 h on d 29, 32, 35, and 38. Ovulatory response to treatment was regarded as ovulation of either the dominant follicle growing at d 30 or the subsequent DF. There was a treatment x day effect (P = .09) on LH pulse frequency, but neither progesterone (CI/ RS+P4) nor progesterone and estradiol (CI/RS+P4+E2) treatment suppressed the calf isolation/restricted suckling-induced increase in LH pulse frequency. The estradiol capsule (CI/RS+P4+E2) delivered sufficient estradiol to delay new follicle wave emergence (treatment x stage; P < .001) and the associated preemergence increase in concentrations of FSH (treatment, P < .05) in cows treated at the postselection stage of follicle wave development, prolonging dominance of the dominant follicle present at treatment initiation (P < .001). The number of cows that ovulated in response to treatment was greater (P < .001) in cows with calf isolation/restricted suckling than in cows suckled ad libitum. Hence, cows assigned to the Ad lib treatment had a longer postpartum interval (P < .001) than cows of the other treatments. Exogenous progesterone treatment increased the frequency of cows exhibiting clinical signs of estrus at first ovulation (P < .001) and reduced the frequency of short estrous cycles (P < .001). We conclude that, in beef cows with calves, a 6-d progesterone treatment does not suppress the calf isolation/restricted suckling-induced increase in LH pulse frequency. Hence, on progesterone withdrawal, the LH pulse frequency is sufficient to stimulate first ovulation, accompanied by overt estrous expression and elimination of a short estrous cycle in most cows. (+info)
Evidence of improving prognosis in heart failure: trends in case fatality in 66 547 patients hospitalized between 1986 and 1995.
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BACKGROUND: Contemporary survival in unselected patients with heart failure and the population impact of newer therapies have not been widely studied. Therefore, we have documented case-fatality rates (CFRs) over a recent 10-year period. METHODS AND RESULTS: In Scotland, all hospitalizations and deaths are captured on a single database. We have studied case fatality in all patients admitted with a principal diagnosis of heart failure from 1986 to 1995. A total of 66 547 patients (47% male) were studied. Median age was 72 years in men and 78 years in women. Crude CFRs at 30 days and at 1, 5, and 10 years were 19.9%, 44.5%, 76.5%, and 87.6%, respectively. Median survival was 1.47 years in men and 1.39 years in women (2.47 and 2. 36 years, respectively, in those surviving 30 days). Age had a powerful effect on survival, and sex, comorbidity, and deprivation had modest effects. One-year CF was 24.2% in those aged <55 years and 58.1% in those aged >84 years. After adjustment, 30-day CFRs fell between 1986 and 1995, by 26% (95% CI 15 to 35, P<0.0001) in men and 17% (95% CI 6 to 26, P<0.0001) in women. Longer term CFRs fell by 18% (95% CI 13 to 24, P<0.0001) in men and 15% (95% CI 10 to 20, P<0.0001) in women. Median survival increased from 1.23 to 1. 64 years. CONCLUSIONS: Heart failure CF is much higher in the general population than in clinical trials, especially in the elderly. Although survival has increased significantly over the last decade, there is still much room for improvement. (+info)
Ultrasonic isolation calls in genetically high- and low-emotional rat pups.
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The present study was undertaken to investigate the relationship between the emotionality and the modulation of ultrasonic vocalizations in Tsukuba High Emotional (THE) and Tsukuba Low Emotional (TLE) strain rat pups 3-18 days old. The THE pups, while isolated from their dam and littermates and placed in a cold environment, emitted ultrasonic isolation calls at a high rate until day 15. In contrast, ultrasound production was at a consistently low level throughout the test period in the TLE pups. The ultrasonic isolation calls of THE pups were attenuated to the same level as those of the TLE pups after administration of diazepam (1 mg/kg, s.c.), a benzodiazepine receptor agonist, at 6 and 12 days of age. These findings suggest that the high emotionality of the rat pups was reflected largely by the emission of ultrasounds in response to isolation distress rather than the number of the benzodiazepine receptors in the brain that might play a role in physiologic mediation of the rat pup isolation call. (+info)
Nithsdale Schizophrenia Surveys. 20. Cognitive function in a catchment-area-based population of patients with schizophrenia.
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BACKGROUND: Cognitive deficits are a core aspect of schizophrenia but there has been no study of cognitive function in a catchment-area-based population of patients with schizophrenia. AIMS: To assess cognitive function in a population of patients with schizophrenia, and relate it to community functioning. METHOD: All patients with schizophrenia in Nithsdale, south-west Scotland, were identified (n = 182). Measures of assessment were: National Adult Reading Test (NART), Mini-Mental State Examination (MMSE), Rivermead Behavioural Memory Test (RBMT), Executive Interview (EXIT), FAS Verbal Fluency and Health of the Nation Outcome Scales (HoNOS). RESULTS: We assessed 138 patients, mean age 48 years (standard deviation (s.d.) 15). Only 14% were in-patients. The mean premorbid IQ as assessed by NART was 98 (s.d. 14); 15% of patients had significant global cognitive impairment (MMSE); 81% had impaired memory (RBMT); 25% had executive dyscontrol (EXIT); and 49% had impaired verbal fluency (FAS). Scores on the functional impairment sub-scale of HoNOS correlated with all measures of cognitive impairment. CONCLUSIONS: Cognitive dysfunction is pervasive in a community-based population of patients with schizophrenia. (+info)
Androgens and isolation from adult tutors differentially affect the development of songbird neurons critical to vocal plasticity.
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Song learning in oscine birds occurs during a juvenile sensitive period. One idea is that this sensitive period is regulated by changes in the electrophysiological properties of neurons in the telencephalic song nucleus lateral magnocellular nucleus of the anterior neostriatum (LMAN), a structure critical for song development but not adult singing. A corollary of this idea is that manipulations affecting the pace and quality of song learning will concomitantly affect the development of LMAN's electrophysiological properties. Manipulations known to affect song development include treating juvenile male zebra finches with exogenous androgens, which results in abnormally truncated adult songs, and isolation of the juvenile from adult tutors and their songs, which extends the sensitive period for song learning. Previously, we showed that synaptic transmission in LMAN changes over normal song development and that these changes are accelerated or retarded, respectively, by androgen treatment and isolation from an adult tutor. The intrinsic properties of LMAN neurons afford another potential target for regulation by steroid hormones and experience of adult tutors. Indeed previous studies showed that the capacity for LMAN neurons to fire action potentials in bursts, due to a low-threshold calcium spike, and the width of single action potentials in LMAN, wane over development. Here we analyzed these and other intrinsic electrophysiological features of LMAN neurons over normal development, then tested whether either early androgen treatment or isolating juveniles from adult tutors affected the timing of these changes. The present study shows that androgen but not isolation treatment alters the developmental time at which LMAN neurons progress from the bursting to nonbursting phenotype. In addition, other intrinsic properties, including the half-height spike width and the magnitude of the spike afterhyperpolarization (AHP), were found to change markedly over development but only changes to the AHP were androgen sensitive. Interestingly of all of the synaptic and intrinsic electrophysiological properties in LMAN studied to date, only the half-height spike width continues to change in the late juvenile stages of song learning. Furthermore raising juveniles in isolation from an adult tutor transiently delays the maturation of this property. The present results underscore that beyond their effects on LMAN's synaptic properties, both androgens and adult tutor experience are potent and selective regulators of the intrinsic properties of LMAN neurons. (+info)
Living arrangements, social integration, and change in functional health status.
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Limited prospective data have examined the association between living arrangements and emotional wellbeing. The authors assessed whether older women living with a spouse were less likely to experience a decline in mental health, vitality, or physical function compared with women living alone or with nonspouse others. The association between living arrangement and 4-year change in functional health status was examined prospectively among 28,324 women aged 60-72 years in the Nurses' Health Study. After adjustment for age, baseline function, comorbid conditions, and health behaviors, women living alone had lower risk of decline in mental health (relative risk (RR) = 0.73, 95 percent confidence interval (CI): 0.65, 0.81) and vitality (RR = 0.72, 95 percent CI: 0.65, 0.80) compared with those living with a spouse. Contact with friends and relatives and level of social engagement were significantly protective against a decline in mental health among women living alone but not among women living with a spouse. These results suggest that women living independently are neither socially isolated nor at increased risk for decline in functional health status. In fact, these women actually fare better on measures of psychologic function than do women living with a spouse. (+info)
Enhanced neurotensin neurotransmission is involved in the clinically relevant behavioral effects of antipsychotic drugs: evidence from animal models of sensorimotor gating.
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To date, none of the available antipsychotic drugs are curative, all have significant side-effect potential, and a receptor-binding profile predictive of superior therapeutic ability has not been determined. It has become increasingly clear that schizophrenia does not result from the dysfunction of a single neurotransmitter system, but rather from an imbalance between several interacting systems. Targeting neuropeptide neuromodulator systems that concertedly regulate all affected neurotransmitter systems could be a promising novel therapeutic approach for schizophrenia. A considerable database is concordant with the hypothesis that antipsychotic drugs act, at least in part, by increasing the synthesis and release of the neuropeptide neurotensin (NT). In this report, we demonstrate that NT neurotransmission is critically involved in the behavioral effects of antipsychotic drugs in two models of antipsychotic drug activity: disrupted prepulse inhibition of the acoustic startle response (PPI) and the latent inhibition (LI) paradigm. Blockade of NT neurotransmission using the NT receptor antagonist 2-[[5-(2,6-dimethoxyphenyl)-1-(4-(N-(3-dimethylaminopropyl)-N-methylcarbamoyl)-2- isopropylphenyl)-1H- pyrazole-3-carbonyl]-amino]-adamantane-2-carboxylic acid, hydrochloride (SR 142948A) prevented the normal acquisition of LI and haloperidol-induced enhancement of LI. In addition, SR 142948A blocked the PPI-restoring effects of haloperidol and the atypical antipsychotic drug quetiapine in isolation-reared animals deficient in PPI. We also provide evidence of deficient NT neurotransmission as well as a left-shifted antipsychotic drug dose-response curve in isolation-reared rats. These novel findings, together with previous observations, suggest that neurotensin receptor agonists may represent a novel class of antipsychotic drugs. (+info)