Role of alpha adrenoceptors in the nucleus accumbens in the control of accumbal noradrenaline efflux: a microdialysis study with freely moving rats.

Microdialysis technique was used to study the effects of the locally applied alpha adrenoceptor agonist phenylephrine and antagonist phentolamine on the basal noradrenaline efflux as well as on the noradrenaline uptake inhibitor desipramine-elicited noradrenaline efflux in the nucleus accumbens (NAc) of freely moving rats. Tetrodotoxin reduced basal noradrenaline efflux by 72%, whereas desipramine increased it by 204%. Phenylephrine reduced the basal noradrenaline efflux by 32% and phentolamine blocked this effect. Phentolamine elevated the basal noradrenaline efflux by 150% and phenylephrine counteracted this effect. The desipramine-elicited noradrenaline efflux was not affected by phenylephrine, but enhanced by phentolamine. Desipramine counteracted the effects of phenylephrine and potentiated those of phentolamine. These results indicate that the accumbal noradrenaline efflux is under inhibitory control of alpha adrenoceptors that are suggested to be presynaptically located on adrenergic nerve terminals in the NAc. Furthermore, this study suggests that the conformational state of alpha adrenoceptors varies across the available amount of noradrenaline. The clinical impact of these data is discussed.

[Studies on the posture of the healthy Japanese child--a classification of posture and their relation to changes in different age groups].

The human standing posture in childhood was analyzed and classified quantitatively utilizing moiré topography and a semi-automated computer system. Three thousand forty-five children ranging from three to twelve years of age were measured. Change in mid-sagittal spinal curvature was analyzed with age. The standing posture in childhood was categorized into three phases. The criteria of the classification of the postures in each phases were defined by alpha. Early juvenile posture: before 7 years of age in both male and female. The main characteristics of this phase is the development in the muscles of lower extremities. Late juvenile posture: 7-9 years old in male and 7-8 years old in female. The development of the lumbar lordosis is most characteristic. Adolescent posture: 10 years or older in male and 9 years or older in female. The increase in segmental length and magnitude of the thoracic kyphosis is most characteristic.