Multiple sclerosis in Mexico: hospital cases at the National Institute of Neurology and Neurosurgery, Mexico City.

The frequency and clinical features of multiple sclerosis (MS) at the National Institute of Neurology and Neurosurgery in Mexico City for the period spanning 1984-1993 is presented. Hospital records of patients with clinically diagnosed MS were selected, the frequency and cumulative frequency of this diagnosis were determined and demographic information and clinical features were recorded. It was found that 70% of the patients were women, 25% were professionals, and 95% were of mixed race.

A longitudinal study of the effects of an L-dopa drug holiday on the course of Parkinson's disease.

Drug holidays as treatment in Parkinson's disease (PD) to ameliorate the effects of chronic L-dopa use are a controversial method. They are used in an attempt to resensitize dopamine receptors in the striatum so that L-dopa therapy can be reinstated at lower doses with fewer of the side effects that normally accompany long-term use of the drug. In the present study, 15 patients with PD were submitted to a 7-day L-dopa drug holiday and then followed for 3 years.

Memory and the septo-hippocampal cholinergic system in the rat.

This study examined the effects of intrahippocampal injections of scopolamine (a muscarinic antagonist drug) on performance of a working-memory task (contingently reinforced T-maze alternation) and a reference-memory task (visual discrimination) by the same rats in the same maze. Rats in the first shipment were trained in delayed alternation, received bilateral implantation of cannulae aimed at the CA 3 field of the dorsal hippocampus, and were tested for retention with 1 microliter microinjections of scopolamine (35 micrograms) and saline on alternate days. These rats were then trained on visual discrimination and tested alternately under scopolamine or saline as described above.