Effects of surgical catheterization and degree of isolation on the behavior and exocrine pancreatic secretion of newly weaned pigs.
(41/807)
The purpose of this study was to examine the effects of surgery and isolation on behavior and exocrine pancreatic secretion of nursery pigs. Thirty-two pigs were weaned at 28 d (d 0) of age and assigned to one of four treatments that comprised the 2 x 2 factorial combination of surgery (surgically modified, intensively handled animals or intact, minimally handled animals) and isolation (fully or partly isolated). The pigs were kept in metabolic crates that provided full or partial isolation for 25 d after weaning. On d 3, one-half of the fully and partly isolated pigs were surgically fitted with a pancreatic catheter, whereas others were left intact. Exocrine pancreatic secretions were collected from catheterized pigs beginning on d 7 and continuing every 2nd d. Behavior of the pigs was video-recorded on d 6 and 13 from 0700 to 2230. There was no indication of treatment effects on the exocrine pancreatic secretion. The volume of pancreatic secretion increased from d 5 to 23, and during the same period the output of protein and enzyme activity also increased. Surgically catheterized pigs showed a passive behavioral response in their undisturbed behavior, characterized by less time spent active, fewer postural changes, less chain manipulation, fewer escape attempts, and less play behavior than their intact littermates. Furthermore, surgical catheterization led to less fear of humans and behavioral indications of an ability to distinguish between familiar and unfamiliar persons. Partial isolation led to increased activity, increased chain manipulation, and increased play behavior, indicating that the provision of limited social contact may help reduce the negative effects of individual housing in weaned pigs. These results suggest that it is important to be aware of effects of housing, experimental surgery, and associated handling when interpreting results from intensive experiments. (+info)
The potential for pharmacological treatment of unpleasant psychological symptoms to increase personal fulfillment in old age.
(42/807)
As some people get older, they experience a decline in their subjective sense of fulfillment. Life may become less rewarding, happiness diminished in intensity. This is usually regarded as an inevitable consequence of the ageing process: regrettable, but a circumstance to which stoical endurance is the only constructive response. This situation is potentially avoidable, for some individuals at least; not at some indefinite point in the future, but now. By using existing and available drugs in a novel fashion to treat the unpleasant psychological symptoms associated with ageing, a substantial improvement in the quality of life may be obtained. (+info)
The effect of isolation on the life-history traits of Pseudosuccinea columella (Pulmonata: Lymnaeidae).
(43/807)
A population of Pseudosuccinea columella was raised under laboratory conditions and its life tables were determined in isolated and paired snails. Isolated snails were significantly larger in shell size than paired snails from five weeks of age onward. Also, statistically significant differences were found for the number of eggs per mass per individual from week 5 to 9, isolated snails exhibiting the highest values. The intrinsic and finite rates of increase were greater in isolated than in paired snails. Either an inhibition of the reproductive output between individuals or the advantage of selfing may be the cause of the differences in this species, acting as a possible mechanism that increase the fitness of isolated snails. (+info)
Dual and opposing modulatory effects of serotonin on crayfish lateral giant escape command neurons.
(44/807)
Serotonin modulates afferent synaptic transmission to the lateral giant neurons of crayfish, which are command neurons for escape behavior. Low concentrations, or high concentrations reached gradually, are facilitatory, whereas high concentrations reached rapidly are inhibitory. The modulatory effects rapidly reverse after brief periods of application, whereas longer periods of application are followed by facilitation that persists for hours. These effects of serotonin can be reproduced by models that involve multiple interacting intracellular signaling systems that are each stimulated by serotonin. The dependence of the neuromodulatory effect on dose, rate, and duration of modulator application may be relevant to understanding the effects of natural neuromodulation on behavior and cognition and to the design of drug therapies. (+info)
Some structural aspects of deviant child behavior.
(45/807)
Covariation within behavior repertoires of problem children were examined. Two boys, referred for psychological help, were observed both at school and at home for about 3 yr. A coded observation system permitted scoring of 19 child-behavior categories and six social-environment categories. After a two-month baseline, behavior categories were intercorrelated, demonstrating that each child showed a group of behaviors that covaried. These groupings were specific to the home and school settings. Contingency management procedures were then applied to each child's problem behaviors in one setting. Next, a reversal phase was instituted, followed by resumption of the initial contingency management phase. These three phases lasted seven months, until the end of the children's public school terms. Results showed that the baseline group of covarying behaviors continued to covary over the three experimental phases. The children then entered a remedial education setting for three summer months, and then returned to schools and were observed in follow-up for 2 yr. The baseline group of behaviors continued to covary during both phases. The behavior covariations could not be accounted for on the basis of temporal relations between the behaviors and social enviroment categories. Although no behavior covariations extended across either child's home and school settings, contingency management procedures produced across-setting effects. (+info)
Social isolation stress impairs the resistance of mice to experimental liver metastasis of murine colon 26-L5 carcinoma cells.
(46/807)
Our previous study has demonstrated that the exposure of male BALB/c mice to social isolation stress caused a suppressed immune response and enhanced liver metastasis of colon 26-L5 carcinoma cells. To more precisely understand the influence of psychosocial factors on the metastatic process, here we have investigated the effect of social isolation stress on the vulnerability of the host to develop liver metastasis of colon 26-L5 cells, including the time span and incidence of metastatic formation, survival time and chemotherapy response. Isolation stress decreased the time period required for the metastasis formation relative to that in controls. On day 7 after the tumor injection, the 75% incidence of tumor metastasis in the stressed mice was 5 times the 15% incidence in the unstressed mice. When exposed to the challenge of lower cell numbers (0.025, 0.05, 0.1 x 10(4)/mouse) of colon 26-L5 cells, mice subjected to isolation stress developed an elevated incidence of metastasis (33.3, 66.6, and 100%, respectively) as compared with the controls (0, 33.3 and 50%, respectively). The survival time following the tumor inoculation was also shorter in the stressed mice (21.83 +/- 1.59d) than in the control mice (24.08 +/- 1.68 d). Furthermore, the response of liver metastasis to chemotherapy consisting of 2 mg/kg cisplatin (CDDP) was worse in the stressed mice than that in unstressed mice. These findings suggested that social isolation stress could significantly impair the resistance of mice to the development of metastasis. (+info)
Juvenile emotional experience alters synaptic inputs on pyramidal neurons in the anterior cingulate cortex.
(47/807)
Analogous to the experience-driven development of sensory systems, the functional maturation of limbic circuits is significantly influenced by early socio-emotional experience. In a combined light and electron microscopic study in the anterior cingulate cortex of Octodon degus, the densities of spine and shaft synapses on apical dendrites of layer III pyramidal neurons were compared in 45 day old (1) undisturbed control animals; (2) handled animals; (3) animals which were repeatedly maternally deprived during the first three postnatal weeks; (4) animals which were treated similarly to group 3 and thereafter kept in chronic social isolation. Animals in groups 2-4 showed significantly higher spine densities (up to 121%, 142% and 151% respectively) compared to control group 1. Group 3 displayed significantly longer apical dendrites compared to control group 1. The electron microscopic analysis in cortical layer II revealed significantly higher spine synapses in group 4 (up to 166%) and fewer shaft synapses in groups 3 and 4 (down to 53% and 65% respectively) compared to group 1. These results demonstrate that early traumatic emotional experience alters synaptic input of pyramidal neurons. Such experience-induced modulation of limbic cortex development may determine psychosocial and cognitive capacities during later life. (+info)
Financial cost of social exclusion: follow up study of antisocial children into adulthood.
(48/807)
OBJECTIVES: To compare the cumulative costs of public services used through to adulthood by individuals with three levels of antisocial behaviour in childhood. DESIGN: Costs applied to data of 10 year old children from the inner London longitudinal study selectively followed up to adulthood. SETTING: Inner London borough. PARTICIPANTS: 142 individuals divided into three groups in childhood: no problems, conduct problems, and conduct disorder. MAIN OUTCOME MEASURES: Costs in 1998 prices for public services (excluding private, voluntary agency, indirect, and personal costs) used over and above basic universal provision. RESULTS: By age 28, costs for individuals with conduct disorder were 10.0 times higher than for those with no problems (95% confidence interval of bootstrap ratio 3.6 to 20.9) and 3.5 times higher than for those with conduct problems (1.7 to 6.2). Mean individual total costs were 70 019 pounds sterling for the conduct disorder group (bootstrap mean difference from no problem group 62 pound sterling; 898 pound sterling 22 692 pound sterling to 117 pound sterling) and 24 324 pound sterling (16 707 pound sterling; 6594 pound sterling to 28 149 pound sterling) for the conduct problem group, compared with 7423 pound sterling for the no problem group. In all groups crime incurred the greatest cost, followed by extra educational provision, foster and residential care, and state benefits; health costs were smaller. Parental social class had a relatively small effect on antisocial behaviour, and although substantial independent contributions came from being male, having a low reading age, and attending more than two primary schools, conduct disorder still predicted the greatest cost. CONCLUSIONS: Antisocial behaviour in childhood is a major predictor of how much an individual will cost society. The cost is large and falls on many agencies, yet few agencies contribute to prevention, which could be cost effective. (+info)