Establishing regional specificity of neuroestrogen action

The specificity of estrogen signaling in brain is defined at one level by the types and distributions of receptor molecules that are activated by estrogens. At another level, as our understanding of the neurobiology of the estrogen synthetic enzyme aromatase has grown, questions have emerged as to how neuroactive estrogens reach specific target receptors in functionally relevant concentrations. Here we explore the spatial specificity of neuroestrogen signaling with a focus on studies of songbirds to provide perspective on some as-yet unresolved questions. Studies conducted in both male and female songbirds have helped to clarify these interesting facets of neuroestrogen physiology

Interpretations of Nature : Contemporary Canadian Architecture, Landscape and Urbanism

From a distinctly Canadian perspective, Kapelos reveals a multiplicity of meanings and constructions which surround the term "nature" in an introduction to the discussion of 42 projects designed between 1979 and 1993. Includes a statement on each project. Bibl. 5 p

Physiological correlates of memory recall in infancy:vagal tone, cortisol, and imitation in preterm and full-term infants at 6 months

We examined the role of physiological regulation (heart rate, vagal tone, and salivary cortisol) in short-term memory in preterm and full-term 6-month-old infants. Using a deferred imitation task to evaluate social learning and memory recall, an experimenter modeled 3 novel behaviors (removing, shaking, and replacing a glove) on a puppet. Infants were tested immediately after being shown the behaviors as well as following a 10-minute delay. We found that greater suppression of vagal tone was related to better memory recall in full-term infants tested immediately after the demonstration as well as in preterm infants tested later after a 10 minute delay. We also found that preterm infants showed greater coordination of physiology (i.e., tighter coupling of vagal tone, heart rate, and cortisol) at rest and during retrieval than full-term infants. These findings provide new evidence of the important links between changes in autonomic activity and memory recall in infancy. They also raise the intriguing possibility that social learning, imitation behavior, and the formation of new memories are modulated by autonomic activity that is coordinated differently in preterm and full-term infants