C van Berkel | PubMed Health

PubMed1993

The environmental connection.

Both the World Health Organization and the Canadian Health for All concept recognize that healthy environments are fundamental to human health. Usually, the responsibility for environmental protection is assigned to public health inspectors. But there is more to a healthy environment than protection. Creating a healthy environment means "altering or adapting our social, economic and physical surroundings in ways that not only preserve but also enhance our health." Clearly, health promotion is an integral part of the concept. As experts in community health promotion, public health nurses (PHNs) could--and should--complement the work of health inspectors.

Canada↗

PubMed1988

Effect of neonatal handling on age-related impairments associated with the hippocampus.

In rats, an environmental manipulation occurring early in life resulted in changes in the adrenocortical axis that persisted throughout the entire life of the animals and attenuated certain deficits associated with aging. Rats handled during infancy had a permanent increase in concentrations of receptors for glucocorticoids in the hippocampus, a critical region in the negative-feedback inhibition of adrenocortical activity. Increased receptor concentrations led to greater hippocampal sensitivity to glucocorticoids and enhanced negative-feedback efficacy in the handled rats. Thus, at all ages tested, rats that were not handled secreted more glucocorticoids in response to stress than did handled rats. At later ages, nonhandled rats also showed elevated basal glucocorticoid levels, with the result that there was a greater cumulative exposure to glucocorticoids in nonhandled rats. Increased exposure to adrenal glucocorticoids can accelerate hippocampal neuron loss and cognitive impairments in aging. Hippocampal cell loss and pronounced spatial memory deficits emerged with age in the nonhandled rats, but were almost absent in the handled rats. Previous work showed that glucocorticoid hypersecretion, hippocampal neuron death, and cognitive impairments form a complex degenerative cascade of aging in the rat. The present study shows that a subtle manipulation early in life can retard the emergence of this cascade.

Aging↗