This study describes the effects of several fixatives and buffers on the morphology of mitochondria from resting and exhausted rats. Rats were run to exhaustion and adjacent portions from the left ventricle or from the soleus were treated with the following fixation procedures: (a) glutaraldehyde buffered with cacodylate, S-collidine, or phosphate…

A discussion of two classes of natural opiate peptides (endorphins and enkephalins) recently found in the brain, and the role they may play in linking emotion and memory. (BB)

Describes the rapid advance of molecular genetics over the past 20 years that have accounted for the origin of mutations. This research has revealed that variation within species is much greater than Darwin postulated. (Author/MA)

Nerve circuits are usually analyzed in terms of the axon, the long fiber of the nerve cell. It now appears that there are many circuits involving only the nerve cell's shorter extensions, the dendrites. (Author/BB)

This literature review delineates the current status of smokeless tobacco, including prevalence, terminology, periodontal effects, and addiction potential. Also discussed is the possible influence on youth of smokeless tobacco use by popular sports figures. (Author/CB)

The paper presents the case of a sixth-grade boy, labeled dyslexic, who responded positively to a biochemical approach. Remedy of iron, zinc, and Vitamin B-6 deficiencies as well as an imbalance of fatty acids resulted in improvements in hair and skin and also in reading. A biochemical approach to behavior problems is proposed. (Author/CL)

Deduces the relationship between reduced velocity and molar fractions for productive enzyme complexes; obtains the mathematical expression of molar fractions for an enzyme with two specific binding sites per molecule; and proposes a useful plot to follow the dependence of enzyme molar fractions with the concentration of one of its ligands. (JN)

Nine elite male distance runners were evaluated by comprehensive periodic monitoring of selected blood chemistry variables, percent body fat and lean body mass, and cardiopulmonary performance as they prepared for the 1984 Olympic Summer Games. Results are discussed. (MT)

Biological evolution can be carried out in the laboratory. With new knowledge available in genetics, possibilities are raised that genetic characters can be transferred in the future to embryos according to a predetermined plan. (PS)

A brief review of research on the neurophysiology and biochemistry of learning. (AK)