Effects of ethanol on development of locus coeruleus brain stem transplants in oculo

Preventive effect of kami-untan-to on performance in the forced swimming test in thiamine-deficient mice: Relationship to functions of catecholaminergic neurons

The kampo (Japanese herbal) medicine "kami-untan-to" (KUT) has been used for a long time in the treatment of neuropsychiatric disorders. We have recently reported that mice put on a thiamine-deficient (TD) diet exhibit a depressive behavior and impairment in avoidance learning after 20 days, and that this impairment was reversed by the chronic administration of KUT. In the present study, we investigated the effect of KUT on the depressive behavior observed in TD mice by using the forced swimming test. Our results show that oral administration of KUT from the 1st day of TD feeding prevented the increased duration of immobility in TD mice. Administration of KUT from the 10th day of TD feeding also had a beneficial effect on depressive behavior. To examine the relationship between the potential effects of KUT on monoaminergic neuronal functions and the depressive behavior observed in TD mice, we measured the immunohistochemical distribution of tyrosine hydroxylase (TH) in the brain using microphotometry. The fluorescence intensity of TH decreased in the limbic cortex and brainstem in TD mice compared with pair-fed mice as the control group, while KUT treatment protected against these decreases. These results suggest that KUT treatment may prevent a sign of depressive behavior, the animal immobility time, induced by TD feeding through a mechanism that involves the decrease of TH in some brain areas of TD mice.

Early postnatal alcohol exposure produced long-term deficits in brain weight, but not the number of neurons in the locus coeruleus

The locus coeruleus (LC), a small nucleus in the pontine tegmentum with clusters of norepinephrine (NE) containing neurons, projects to more brain regions than any other nucleus in the central nervous system. Therefore, any neuroanatomical deficits in the LC may have wide-ranging functional implications. Previous studies have shown that heavy alcohol exposure during development can damage several brain regions receiving extensive innervation from the LC (e.g., cerebellum and olfactory bulb). In this study, we examined the effects of early alcohol exposure during development on neuronal numbers in the LC of the adult rat. Sprague-Dawley rat pups were reared using artificial rearing techniques during the brain growth spurt period (part of the third trimester equivalent). The pups in the alcohol group received 4.5 g/kg per day in two of their 12 daily feedings from postnatal days (PDs) 4-9. Gastrostomy and suckle control groups were also included. On PD 90, the animals were sacrificed and their brains were processed for stereological cell counting. Whole brain weight, the number of neurons in the LC, the volume and neuronal density of the LC were assessed. There was a significant reduction in whole brain weight of the alcohol group compared with that of the gastrostomy control group, demonstrating a long lasting effect of alcohol on overall brain growth. Nevertheless, there were no differences in neuronal number, density and volume of the LC between alcohol and gastrostomy groups. Results were discussed in relation to the issues of temporal and regional vulnerabilities.