Rats were trained both to barpress for and escape from locus coeruleus, midbrain periaqueductal gray and hypothalamic stimulation. Rate-intensity functions for intracranial self-stimulation (ICSS) behavior and latency-intensity functions for escape behavior were obtained for each electrode site in each animal. Following baseline, d-amphetamine was administered and responding was compared with the saline condition for both rate-intensity and latency-intensity functions. ICSS response rates were enhanced by d-amphetamine at all loci, particularly at threshold intensities, while escape responding was biphasically affected by d-amphetamine at all loci. D-amphetamine increased escape latencies at intensities which, under saline, elicited short escape latencies, while decreasing escape latencies at intensities which, under saline, elicited long escape latencies. A significant correspondence was noted between intensities which, under the influence of d-amphetamine, both elicited longer escape latencies and higher ICSS response rates, suggesting that in both ICSS and escape paradigms, animals were titrating the duration of the stimulus train. No site-specific effects of d-amphetamine upon escape behavior were noted.

Animals↗

PubMedDate not supplied

The influence of education and experience on ethical attitudes in neonatal intensive care.

A cross-sectional survey of medical students, pediatrics residents, and neonatologists attempted to identify the combined influence of education and experience on ethical attitudes regarding the management of infants weighing less than 750 g at birth. Of the 120 people surveyed, 94 (78%) returned usable surveys. All groups rated quality of life the most important criterion in treatment decisions. Conversely, cost was rated least important by each group. In addition, cost was rated relatively more important by the clinical medical students than by the preclinical students, residents, or neonatologists. The neonatologist was rated the most important decision maker by the neonatologists and the residents. The parents were rated most important by both groups of students. Severe mental retardation was regarded as an unacceptable quality of life by 82% of the neonatologists, 63% of the residents, 61% of the clinical students, and 48% of the preclinical students. Severe cerebral palsy was considered an unacceptable quality of life by 73% of the neonatologists, 63% of the residents, 50% of the clinical students, and only 32% of the preclinical students. Finally, the anticipated long-term outcome of extremely-low-birth-weight infants was viewed more positively by the neonatologists than by the other groups surveyed.

Adult↗