Nutritional factors modify the inhibition of CNS development by combined exposure to methadone and ethanol in neonatal rats.

The consequences resulting from the combined exposure to methadone and ethanol during a time period equivalent to the third trimester brain growth spurt was the purpose of this study. Rat pups were treated on postnatal days 6-10 and sacrificed on postnatal day 11. Body weight along with the heart, liver, kidneys, whole brain, cerebrum, cerebellum, and brain stem weights were measured. The impact of nutritional factors were identified by delivery of the drug solutions in one of two intubation vehicles differing in both caloric density and composition. Ethanol and methadone in combination result in significantly increased detrimental effects compared to methadone alone only when possible nutritional compromise was present. The combined effect of both drugs significantly inhibited body growth and the development of all brain regions studied. Neither drug alone, nor in combination, produced significant inhibition of growth in the liver, heart, or kidney. The nutritional status of the pup, as represented by vehicle composition, was able to modify the specific drug effects and suggests that nutritional status can mask or enhance the determination of specific drug effects.

Strength training in spastic hemiparesis: should it be avoided?

Controversy exists between accepted principles of strength training and one of our popular neurological therapeutic exercise approaches. Graded resistive exercise is a common method of strength training in the general population. Bobath avoided resistive exercise with post-stroke individuals with spasticity suggesting that the use of effort would only increase cocontraction and reduce coordination. Bobath's theories remain unsupported. The purpose of this study was to test the clinical assumption that graded resistive exercise leads to loss of force production and force modulation in spastic subjects in such a way that spasticity and cocontraction increases and force control is reduced. Nine subjects with a diagnosis of stroke with left hemiplegia and evidence of spasticity in the left biceps performed graded resistive exercise with simultaneous measurements of cocontraction, spasticity levels, and fractionated reaction time. The results of this study indicated that there was little difference between the effects of graded exercise on the performance of paretic and non-paretic muscle. When differences were found, resistive exercise appeared to have a beneficial effect on the performance of paretic muscle. The results of this study suggest that graded resistive exercise is not detrimental to post-stroke spastic muscle, and should be considered as a possible remediation for the deficits of muscle weakness and reduced function in post-stroke individuals.

Alteration of dopamine metabolism in different brain regions of the rabbit by estradiol and tamoxifen.

Tamoxifen citrate, a mixed estrogen agonist-antagonist, and estradiol 17-beta administered separately for 14 days significantly reduced dopamine and dihydroxyphenylacetic acid in the cortex and hypothalamus regions of the brain in immature female rabbits. In addition to these areas, estradiol also reduced dopamine and dihydroxyphenylacetic acid in the striatum but tamoxifen treatment significantly reduced only dihydroxyphenylacetic acid concentration in the striatum. When estradiol and tamoxifen were injected together, dopamine and dihydroxyphenylacetic acid concentrations were reduced only in the cortex. Specific binding of [3H]spiperone to dopamine receptors was significantly increased by both estradiol and tamoxifen in the hypothalamus but only tamoxifen increased dopamine binding in the striatum. A low dose of tamoxifen, either alone or in combination with estradiol, increased uterine weight, but a higher dose of tamoxifen was neither an estrogen agonist nor antagonist. These studies indicate that estradiol and tamoxifen alter dopamine metabolism in the various regions of brain differentially. The estrogen agonist activity of tamoxifen does not correspond to antidopaminergic action of estradiol in the striatum.