THE CENTRAL NERVOUS SYSTEM OF CHAMELEON VULGARIS

An analysis of the brain of Chameleon has given evidence of a number of modifications in the general plan of the reptilian nervous system. The telencephalon shows a reduced olfactory mechanism and suggests the presence of the true motor cortex. The ventral peduncle of the lateral forebrain bundle is unusually large with the majority of its fibres terminating in two new nuclear masses in the hypothalamus, the nucleus entopeduncularis, and a few in the nucleus ruber. A high degree of effective response to optic stimuli is indicated by the extensive correlation between the optic tectum and the nuclear masses of the midbrain and the diencephalon. The wide range of eye movements is probably correlated with the development of the basal optic root ganglion and its numerous secondary connections and the elaborate relationship of the geniculate complex. The usually highly developed tecto-bulbar system is partly replaced by a large tegmento-bulbar system that relays the tectal impulses caudally. An interesting mesencephalic nucleus is a large nucleus profundus mesencephali that receives a great variety of impulses and appears to be an important correlation center. Ascending visceral mechanisms were described bringing the hypothalamus into relationship with the lower centers. The great excursion of the tongue is associated with a highly differentiated hypoglossal nucleus. Components of the medial lemniscus from the spinal cord and the medulla to the vicinity of the thalamus were demonstrated.     

大鼠中枢神经系统一氧化氮对电针镇痛作用影响的研究

中枢神经系统一氧化氮 (ｎｉｔｒｉｃｏｘｉｄｅ,ＮＯ)在痛和痛觉调制过程中的作用及其机制 ,受到国内外广泛关注 ,积累了大量的实验资料。但迄今为止 ,电针 (ＥＡ)镇痛时中枢神经系统ＮＯ的作用及其机制尚不清楚。本工作电针大鼠双侧“足三里”穴 ,观察向大鼠侧脑室微量注射ＮＯ前体和供体物质、一氧化氮合酶 (ＮＯＳ)抑制剂以及血红蛋白 (Ｈｂ)、亚甲基蓝 (ＭＢ)等 ,对大鼠痛和电针镇痛作用的影响 ,试图探讨ＮＯ在中枢神经系统痛觉调制和针刺 (电针 )镇痛过程中的作用及其机制。1　材料与方法健康Ｗｉｓｔａｒ大鼠 ,雌雄不拘 ,体重 2 10～…     

ERGOTHIONEINE IN THE CENTRAL NERVOUS SYSTEM

Abstract— Further investigations have been made into ergothioneine in the brains of several mammalian species, and the distribution of ergothioneine in the brain of the ox is described. It has not been possible to confirm many of the findings of earlier workers and the results do not appear to support their conclusion that ergothioneine is identical with the cerebellar factor.     

SYNAPSES IN THE CENTRAL NERVOUS SYSTEM

A number of different synapses have been described in the medulla, cerebellar cortex, and cerebral cortex of the rat. All of these possess the same fundamental fine structure as follows: 1. Close apposition of the limiting membranes of presynaptic and postsynaptic cells without any protoplasmic continuity across the synapse. The two apposed membranes are separated by a cleft about 200 A wide, and display localized regions of thickening and increased density. 2. The presynaptic expansion of the axon, the end-foot or bouton terminal, contains a collection of mitochondria and clusters of small vesicles about 200 to 650 A in diameter. Although the significance of these structures in the physiology of the synapse is still unknown, two suggestions are made: that the mitochondria, by means of the relation between their enzymatic activity and ion transport, participate in the electrical phenomena about the synapse; and that the small synaptic vesicles provide the morphological representation of the prejunctional, subcellular units of neurohumoral discharge at the synapse demanded by physiological evidence.     

LIPID COMPOSITION OF THE CENTRAL NERVOUS SYSTEM OF MARINE VERTEBRATES

—The lipid composition of the central nervous system of some marine vertebrates and two mammalian species (rat and man) was analysed by one- and two-dimensional quantitative thin-layer chromatography, and the cerebroside fatty acids were analysed by gas chromatography. The concentrations of sphingomyelin and cerebrosides are higher in mammals than in fishes, while no significant differences are observed for other lipid classes. Furthermore, in mammals the ratio between hydroxy and normal fatty acids in the cerebrosides is much higher than in fishes. The cerebrosides of mammals contain more very long chain fatty acids than those of marine vertebrates.     

THE SPECIFICITY AND SULFHYDRYL SENSITIVITY OF THE INOSITOL TRANSPORT SYSTEM OF THE CENTRAL NERVOUS SYSTEM

Abstract— The transport of two cyclohexitol stereoisomers, myo-inositol (inositol) and scyllo-inositol (scyllitol), from blood into the CNS in vivo and into the choroid plexus in vitro was studied. In vitro , the uptake of [³H]scyllitol or [³H]inositol by choroid plexuses, isolated from rabbits and incubated in artificial CSF, was measured. Both scyllitol and inositol inhibited [³H]scyllitol or [³H]inositol accumulation by the choroid plexus. Inositol competitively inhibited [³H]scyllitol accumulation and both isomers had a comparable affinity (K_t= 0.1 m m ) for the single cyclohexitol accumulation system. The other 6 stereoisomers tested had an order of magnitude less affinity for the cyclohexitol accumulation system of choroid plexus. Thiol reagents that penetrate cells inhibited inositol accumulation by choroid plexus more effectively than nonpenetrating thiol reagents. In vivo , in unanesthetized rabbits. the transport of unmetabolized [³H]inositol from blood into CSF, choroid plexus and brain was readily saturated by increasing the plasma levels of myo-inositol but not by the stereoisomer d -chiroinositol. Similarly, the transport of unmetabolized [³H]scyllitol into CSF, brain and choroid plexus was readily saturated by increasing the plasma levels of myo-inositol. Beside documenting the stereospecificity and thiol reagent sensitivity of the inositol transport mechanism of the choroid plexus, these results provide further evidence that the choroid plexus is a locus for cyclohexitol transport between blood and CSF. Moreover, they show that scyllitol, which, like inositol, is present at a higher concentration in brain than plasma, can be transported from blood into CSF and brain by the same system that transports inositol.     

THE VALUE OF THE PULMONATE CENTRAL NERVOUS SYSTEM IN PHYLOGENETIC HYPOTHESIS

Study of the pattern of fusion of the ganglia of the visceralchain of pulmonates provides invaluable information for determiningthe direction of evolution at a local level in particular lineages.Information derived from the study of the procerebrum aloneis unlikely to be adequate to construct a phylogeny of the Pulmonata. (Received 25 May 1977;