Bidirectional effects of voluntary exercise on the expression of Bdnf isoforms in the hippocampus of Hatano rat strains displaying different activity levels.

Brain-derived neurotrophic factor has functional mRNA isoforms, whose expression is assumed to mediate the beneficial effects of exercise in neuropsychiatric disorders. This study aims to reveal the mechanism of intensity-dependent effects of voluntary exercise, focusing on the expression of Bdnf mRNA isoforms in Hatano rats. Animals with different voluntary activity were housed in cages with a locked or unlocked wheel for 5 weeks. The expression levels of Bdnf isoforms and the corresponding coding sequences (CDS) were measured in the hippocampus using real-time polymerase chain reaction (PCR). We found that exercise increased the expression of Bdnf isoform containing exon 1 in the high-intensity-running strain and decreased the expressions of Bdnf exon 1, 3, 6, 7, 8, and 9a in mild-intensity-running animal. The expression of Bdnf CDS was increased by exercise in both strains. These results suggest that expressions of Bdnf isoforms depend on the intensities of voluntary exercise, but the involvement of subjects' genetic background could not be excluded. Our finding also implies that the bidirectional effects of exercise may not be mediated via the final product of Bdnf.

Possible effects of voluntary exercise intensity on anxiety-like behavior and its underlying molecular mechanisms in the hippocampus: Results from a study in Hatano rats.

The prevalence of neuropsychiatric diseases, including anxiety disorders, has increased in recent years. A better understanding of the mechanisms mediating symptoms in these disorders is essential for developing treatments. Although voluntary exercise can alleviate symptoms, its anxiolytic effect varies with the intensity of the activity. Therefore, to investigate the usefulness of voluntary exercise in alleviating the symptoms of neuropsychiatric disorders, assessing its effect based on intensity is required. Hatano rats, consisting of high- and low-avoidance animals (HAA and LAA, respectively), differ in their propensity to voluntary exercise. These animals are useful for examining the effects of voluntary running activity differing in intensity on anxiety-like behavior. We housed Hatano rats in cages containing locked or unlocked running wheels starting at 4 weeks of age, conducted elevated plus maze test at 8 weeks of age, followed by plasma corticosterone measurement and DNA microarray analysis on hippocampal tissue at 9 weeks of age. Our results show that only LAA (mild-intensity running animals), but not HAA (high-intensity running animals), had reduced anxiety-like behavior without plasma corticosterone change. In addition, LAA had increased immunity-related gene expression, but decreased proteolysis-related gene expression. Our findings suggest that mild-intensity voluntary running mediates the anxiolytic effect of exercise and is regulated through increasing the expression of immunity-related genes or decreasing the expression of proteolysis-related genes in the hippocampus.

Conformational and Optical Characteristics of Unidirectionally Twisted Binaphthyl-Bipyridyl Cyclic Dyads.

An axially chiral binaphthyl-bipyridyl cyclic dyad in which the two units are connected by short -CH2O- linkers was synthesized. Experimental and theoretical analyses indicate that the (R)-binaphthyl unit in the dyad induces (R)-chirality in the bipyridyl unit, both in the solid state and in solution. It is shown that vibrational circular dichroism (VCD) is useful to determine the twisting pattern of 2,2'-bipyridyl compounds. The dyad shows crystallization-induced emission enhancement (CIEE).