Acta Physiologica Scandinavica 

About: Acta Physiologica Scandinavica is an academic journal. The journal publishes majorly in the area(s): Skeletal muscle & Stimulation. Over the lifetime, 11427 publications have been published receiving 458286 citations.

Stereotaxic mapping of the monoamine pathways in the rat brain.

Abstract: The ascending monoamine pathways in the rat brain are demonstrated by the pile up of fluorescent material occurring in the axons after various types of lesions. The anatomy of the pathways is outlined in drawings of frontal sections of the brain and the origin and termination of several pathways is determined by studying the anterograde and retrograde degeneration occurring after well localised lesions. It is possible to separate the ascending NA pathways into a dorsal and a ventral bundle of axons. The dorsal bundle innervates the cortex and the hippocampus and the ventral bundle supplies NA nerve terminals to the medulla, the pons, the mesencephalon and the diencephalon. The dorsal bundle is found to originate in the locus coeruleus. Lesions of this nucleus abolish the nerve terminals in all cortical areas and in several other areas of the brain indicating a unique role for the locus coeruleus in influencing the activity of the entire brain. The 5-HT pathways have a distribution similar to the ventral NA pathyway. The course of the nigro-striatal and the meso-limbic DA pathways is presented in detail.

Dynamic response of chest wall and lung injuries in rabbits exposed to air shock waves of short duration.

Abstract: The movements of the chest walls of rabbits exposed to steep-fronted air shock waves of short duration produced by 50 g spherical charges of TNT were recorded by means of a mechano-electric motion transducer originally developed for this investigation. The main purpose has been to study the correlation between the deformations of the chest and the damage inflicted to the underlying organs, especially the lungs. The motion parameters, amplitude, velocity and acceleration of the chest wall, were correlated to the physical characteristics of the shock wave as well as to the lung injury produced. The lung injuries were found to be highly correlated to the impulse of the incident shock wave, and also, although to a lesser degree, to the maximum overpressure of the shock wave, and to the velocity and acceleration acquired by the chest wall. The correlation of the lung injuries to the maximum amplitude of the inward displacement of the chest wall, on the other hand, was found to be much lower or even uncertain. The following critical values of the motion parameters were established. If the chest wall receives an impulse load of such a strength and duration that an inward relative movement results with a velocity of more than 15 m se& attained within a period of time of 150–200 ps, i. e. involving accelerations of the order of 104g, there is a high probability that a severe lung injury will result. Corresponding maxi mum amplitudes of the displacement of the chest wall were 5 to 7 mm. The lower limit of effective reflection pressures and impulses causing severe lung injuries were 10 bar and 1.5 gf sec cm-2, respectively. The biomechanical events occurring in the exposed chest are discussed in some detail.

Postsynaptic supersensitivity after 6-hydroxy-dopamine induced degeneration of the nigro-striatal dopamine system.

Abstract: The effect of L-DOPA and the dopamine (DA) receptor stimulating drug apomorphine was studied in rats after unilateral degeneration of the nigrostriatal DA system by intracerebral injection of 6-hydroxydopamine. Both apomorphine and L-DOPA induced a strong rotational behaviour which was registered in a specially designed “rotameter”. The direction of the rotation indicated that the denervated striatum was more sensitive to DA receptor stimulating drugs than the innervated striatum. This supersensitivity probably corresponded to the decentralisation type of supersensitivity in the peripheral nervous system although it developed faster. The action of L-DOPA was inhibited by pretreatment with the DOPA-decarboxylase inhibitor Ro4–4602 which indicated that L-DOPA must be converted to DA in order to stimulate the supersensitive postsynaptic cells. Pretreatment with a single dose of reserpine also induced supersentitivity to apomorphine which reached its maximum on the 3rd day and then decreased on the 4th day. Postsynaptic supersensitivity after degeneration of the nigro-striatal DA system is probably an important reason for the effectiveness of the L-DOPA therapy against Parkinson's disease.