Reduced expression of the vesicular acetylcholine transporter causes learning deficits in mice.

Storage of acetylcholine in synaptic vesicles plays a key role in maintaining cholinergic function. Here we used mice with a targeted mutation in the vesicular acetylcholine transporter (VAChT) gene that reduces transporter expression by 40% to investigate cognitive processing under conditions of VAChT deficiency. Motor skill learning in the rotarod revealed that VAChT mutant mice were slower to learn this task, but once they reached maximum performance they were indistinguishable from wild-type mice. Interestingly, motor skill performance maintenance after 10 days was unaffected in these mutant mice. We also tested whether reduced VAChT levels affected learning in an object recognition memory task. We found that VAChT mutant mice presented a deficit in memory encoding necessary for the temporal order version of the object recognition memory, but showed no alteration in spatial working memory, or spatial memory in general when tested in the Morris water maze test. The memory deficit in object recognition memory observed in VAChT mutant mice could be reversed by cholinesterase inhibitors, suggesting that learning deficits caused by reduced VAChT expression can be ameliorated by restoring ACh levels in the synapse. These data indicate an important role for cholinergic tone in motor learning and object recognition memory.

Physicians' attitudes, recommendations and practice of male and female sterilization in São Paulo.

While prevalence of vasectomy is low in Brazil, female sterilization is very high. The potential for growth of vasectomy services may be related to attitudes and practices of physicians. In 1984, 660 physicians at seven major hospitals in São Paulo were randomly selected from a total population of 2207 physicians in these hospitals. They were interviewed about their attitudes towards family planning in general, and specifically towards voluntary sterilization. A high degree of vasectomy among this medical community is indicated by its relatively high prevalence among married physicians and their spouses; about one in ten reported that either they or their spouse had had a vasectomy. Half of the physicians who perform sterilizations perform vasectomies: 22% of obstetricians and gynecologists, 85% of surgeons, and all urologists. In general, physicians would recommend vasectomy and tubal ligation equally often to their clients. Depending on the circumstances, up to 85% of all physicians recommend some sterilization procedure. Recommendation was modified by the type of procedure a physician performed, and by the patient's characteristics. Physician's recommendations of sterilization increased with age and parity of patient and was related to the health conditions and socioeconomic circumstances of the couple.