RESUMO
Despite decades of research with humans, the biological mechanisms that motivate an individual to help others remain poorly understood. In order to investigate the roots of pro-sociality in mammals, we established the helping behavior test, a paradigm in which rats are faced with a conspecific trapped in a restrainer that can only be opened from the outside. Over the course of repeated test sessions, rats exposed to a trapped cagemate learn to open the door to the restrainer, thereby helping the trapped rat to escape (Ben-Ami Bartal et al., 2011). The discovery of this natural behavior provides a unique opportunity to probe the motivation of rodent helping behavior, leading to a deeper understanding of biological influences on human pro-sociality. To determine if an affective response motivates door-opening, rats receiving midazolam, a benzodiazepine anxiolytic, were tested in the helping behavior test. Midazolam-treated rats showed less helping behavior than saline-treated rats or rats receiving no injection. Yet, midazolam-treated rats opened a restrainer containing chocolate, highlighting the socially specific effects of the anxiolytic. To determine if midazolam interferes with helping through a sympatholytic effect, the peripherally restricted beta-adrenergic receptor antagonist nadolol was administered; nadolol did not interfere with helping. The corticosterone response of rats exposed to a trapped cagemate was measured and compared to the rats' subsequent helping behavior. Rats with the greatest corticosterone responses showed the least helping behavior and those with the smallest responses showed the most consistent helping at the shortest latency. These results are discussed in terms of their implications for the interaction between stress and pro-social behavior. Finally, we observed that door-opening appeared to be reinforcing. A novel analytical tool was designed to interrogate the pattern of door-opening for signs that a rat's behavior on one session influenced his behavior on the next session. Results suggest that helping a trapped rat has a greater motivational value than does chocolate. In sum, this series of experiments clearly demonstrates the fundamental role of affect in motivating pro-social behavior in rodents and the need for a helper to resonate with the affect of a victim.
RESUMO
OBJECTIVES: : The symptom experience of community-dwelling persons with dementia adopting an open-ended approach has not been well documented. We sought to identify the most bothersome symptoms experienced using self and caregiver report, and to evaluate whether these symptoms are captured by commonly used symptom-assessment measures including the Edmonton Symptom Assessment System (ESAS, standard in palliative care), Neuropsychiatric Inventory (NPI), and End-of-Life Dementia Scale-Symptom Management (ELDS-SM). DESIGN: : The authors use data from the Palliative Excellence in Alzheimer Care Efforts (PEACE) study to characterize the symptom experience. SETTING: : PEACE included outpatient primary care geriatric patients in an urban setting affiliated with the University of Chicago. PARTICIPANTS: : Data were examined from the 150 patient-caregiver dyads. MEASUREMENTS: : The most bothersome symptoms of persons with dementia during the past week were reported separately by self and family caregiver. Symptoms were asked in an open-ended format and qualitative analysis using constant comparative technique was applied for each response. Reports were categorized and frequencies tabulated. RESULTS: : One hundred fifteen persons (35 could not respond to the interview questions) with dementia reported 135 symptoms (median 1, range: 0-3). The most frequently reported symptoms were pain (N = 48; 42%), depression (N = 13; 11%), cognitive deficit (N = 12; 10%), anxiety (N = 7; 6%), and ophthalmologic complaint (N = 5; 4%). One hundred fifty caregivers reported 259 symptoms (median 2, range: 0-5) with cognitive deficit (N = 71; 47%), pain (N = 46; 30%), depression (N = 26; 17%), activity disturbance (N = 23; 15%), and thought and perceptual disturbances (N = 12; 8%) being reported most frequently. The ESAS, NPI, and ELDS-SM missed two or more of the most commonly reported symptoms by dyads of persons with dementia and their family caregivers. CONCLUSION: : Symptoms were frequently reported by persons with dementia and their caregiver; however, commonly used symptom assessment measures overlooked important symptoms. All physicians should be vigilant about screening for both psychologic and physical symptoms in this population.