* Cortex Pharmaceuticals Inc., of Irvine, Calif., began a Phase I/IIa trial of Ampalex for Alzheimer's disease in collaboration with the National Institutes of Health, of Bethesda, Md. The placebo-controlled study will involve 16 patients with mild to moderate Alzheimer's disease. Ampalex is designed to combat loss of neurons and prevent deterioration of cognitive functions.

* Interneuron Pharmaceuticals Inc., of Lexington, Mass., said it will buy 200,000 shares of its subsidiary, Intercardia Inc., which was formed to develop cardiovascular and pulmonary disease drugs. Interneuron currently owns 60 percent of Intercardia.