Effect of diabetes and aging on human sympathetic autonomic ganglia.

Although autonomic dysfunction frequently complicates the clinical course of patients with diabetes, relatively little is known of its underlying neuropathology. Using experimental animal models as a guide, the prevertebral superior mesenteric (SMG) and paravertebral superior cervical (SCG) sympathetic ganglia have been examined in a series of adult autopsied diabetic and non-diabetic patients of various ages using histochemical, ultrastructural, morphometric, and immunohistochemical methods. Quantitative studies demonstrated that markedly swollen argyrophilic terminal axons (neuroaxonal dystrophy) containing large numbers of disorganized neurofilaments developed in the SMG but not SCG as a function of diabetes, increasing age, and gender (males were more severely affected than females). As in experimental animals, diabetic (types I and II) patients developed histologically identical lesions prematurely and in greater numbers than age-matched nondiabetic patients. Morphometric studies showed a small but statistically significant decrease in neuronal density in the SMG but not SCG of diabetic patients. The dimensions of individual sympathetic neurons were not significantly different in aging or diabetes. The pathological lesions identified in the SMG may contribute to the autonomic dysfunction so commonly observed in diabetic patients.     

Neuroaxonal dystrophy in Australian Merino lambs

Neuroaxonal dystrophy (NAD) is a morphological abnormality in man and animals that is characterized by the occurrence of numerous axonal swellings (spheroids) in the nervous system. NAD has been described in Suffolk lambs in the USA, Merino lambs in Australia and several breeds of sheep in New Zealand. This paper describes the clinicopathological changes of only the second occurrence of NAD reported in Merino lambs. There were some features (myelin loss, gliosis and visual impairment) in these Australian cases that have not been reported previously in ovine NAD. Application of immunohistochemical markers of axonal transport suggested that disruption of this transport mechanism contributed to spheroid development.     

Calretinin immunoreactivity in human sympathetic ganglia

Calretinin is an EF-hand calcium-binding protein involved in the maintenance of intracellular calcium ion homeostasis. This study was understaken to investigate the presence of calretinin in human lumbar paravertebral sympathetic ganglia from subjects of different ages (26–85 years) using immunohistochemical and immunoblotting methods. Calretinin-like immunoreactivity was found in a subpopulation of postganglionic sympathetic neurons, whose percentage decreased progressively with aging by about 50% (63% of immunoreactive neurons at 40 years; 29% at 81 years) whereas the neuronal density remained basically unchanged. Calretinin-like immunoreactivity showed a granular pattern of cytoplasmic distribution suggesting preferential localization of this protein associated with intracellular membranes. Occasionally diffuse cytosolic labelling was also observed. The immunoblotting demonstrated a protein band with an estimated molecular weight of 30 kDa, approximately. Present results provide, for the first time, evidence for the presence of calretinin in human paravertebral sympathetic ganglia. Since the number of calretinin-like immunoreactive neurons decreased significantly with aging our findings suggest an involvement of this protein in the age-dependent impairment of sympathetic function.     

Nerve endings in human sympathetic ganglia

Forty-eight human sympathetic ganglia from 22 sympathectomies were examined ultrastructurally after one of three different fixations: (1) glutaraldehyde + osmium tetroxide, (2) glutaraldehyde + potassium dichromate + osmium tetroxide, or (3) potassium permanganate. Three different kinds of synapsing nerve ending could be identified after all fixation schedules. Type 1: “Cholinergic,” containing small, agranular vesicles 40–60 nm in diameter (75% of all vesicles) and some large granular vesicles (100 nm in diameter). The number of type 1 profiles decreased with increasing age. Type 2: “Adrenergic,” containing small granular vesicles 40–70 nm in diameter (over 90% of the vesicles). Type 3: “Nonadrenergic, noncholinergic,” characterized by large opaque vesicles 80–160 nm in diameter (over 50% of all vesicles). The frequencies of the types were counted after potassium permanganate fixation: type 1–71%, type 2–23%, and type 3–6%. In addition, at least two types of nerve profiles were observed which did not form synapses: (1) profiles entirely filled with mitochondria (mitochondrial accumulation), and (2) large nerve profiles full of different kinds of vesicles, myelin figures, and mitochondria (axonal dilatation). It is concluded that the sympathetic ganglion cells receive cholinergic and adrenergic innervation and also a third type of innervation, the possible peptidergic nature of which is discussed.     

Immunopathology and microvascular lesions in human sympathetic ganglia

Lumbar sympathetic ganglia surgically removed from adult patients affected by obstructive peripheral arteriopathies are investigated with traditional histology and fluorescent antibody technique. The presence of various pictures of microangiopathy is confirmed, mainly haemodynamic (hyaline-oedematous perivascular thickening) phenomena. Since specific fluorescence is absent from any lesion, the autoimmune pathogenic hypothesis may be discarded.     

Age related heterogeneity of lipopigments in human sympathetic ganglia

The histochemical, autofluorescence and morphological characteristics of lipopigments accumulating with age in the human sympathetic neurons were studied. The spectral characteristics of the lipopigment autofluorescence change with age suggesting the accumulation of additional components in the residual bodies. This component is electron microscopically highly osmiophilic and stains also with silver staining. These changes may indicate the gradual melanization of the lipopigments due to auto-oxidation of catecholamines. The accumulation of the melanized form of lipopigment may be a sign of more advanced cellular trauma.     

Microspectrofluorometric quantitation of autofluorescent lipopigment in the human sympathetic ganglia

The age-related changes in lipopigment autofluorescence were studied by microspectrofluorometry in three different types of human neurons: the sympathetic neurons of the stellate and superior mesenteric ganglion and pyramidal neurons of the frontal cortex. The age-related increase in lipopigment autofluorescence was more rapid in stellate ganglion but similar linear increases were found also in superior mesenteric ganglion and frontal cortex. There was an age-related shift in the autofluorescence from yellow to orange in the ganglia. This may be due to the accumulation of neuromelanin in noradrenergic neurons. Lipopigments were identified in sympathetic neurons at the age of 4 months and all neurons carried pigment granules after the age of 64 years. It is concluded that lipopigment autofluorescence is a useful marker for cellular ageing in both the peripheral and the central nervous system.     

The development of synaptophysin immunoreactivity in the human sympathetic ganglia

Using an indirect immunohistochemical method, synaptophysin immunoreactivity (SYN-IR) has been studied in cryostat sections of stellate and thoracic ganglia in human fetuses, neonates, infants and adults. In the course of development, a progressive increase in SYN-IR in axonal terminals and around nerve cells was demonstrated. In contrast, large clusters of small intensely fluorescent (SIF) cells and paraganglionic cells increased in number in fetuses and premature neonates at 24-25 weeks. Such SIF cell clusters varied in form and often occurred at pole or subcapsular areas of sympathetic ganglia close to blood vessels or paraganglia. With increasing gestational age and during infancy, a decrease in sizes of SIF cell groups and paraganglionic cells as well as changes in their distribution were found. The results show that the amount and distribution of SYN-IR is temporally related to the maturation and functional activity of human sympathetic ganglia neurons. It was suggested that numerous SIF cells and paraganglia in human prenatal sympathetic ganglia were both indicative of incomplete cell migration and an important source of regulation of ganglionic microcirculation under the conditions of relative hypoxia and immature nervous regulation.     

Neuroaxonal dystrophy associated with vitamin E deficiency in two Haflinger horses

Neuroaxonal dystrophy and minimal diffuse degenerative myelopathy was diagnosed in two female full sibling, 1- and 2-year-old, Haflinger horses. Both animals developed slowly progressive ataxia from the age of 4 months. Clinical signs, which were more prominent in the hind legs, included hypermetria and dysmetria. Histological examination revealed neuroaxonal dystrophy characterized by spheroid formation, vacuolation, astrogliosis and lipofuscin pigment deposition in macrophages and neuronal perikarya. These changes were restricted to the gracilis and cuneate nuclei, nucleus of the solitary tract, nucleus intermediomedialis in the sacral and the seventh segment of the cervical spinal cord and Stilling-Clarke's column in both horses and the medial vestibular nucleus in the older horse. Both diseased Haflingers had significantly reduced serum alpha- and gamma-tocopherol values. No significant alteration in serum total lipid concentrations and serum selenium values were observed. It is likely that the condition has a familial hereditary basis. It is unclear whether there is a link between the observed neuroaxonal dystrophy and vitamin E deficiency and further investigations are warranted.     

Bombesin-like immunoreactivity in sympathetic ganglia

Nerve fibres showing immunoreactivity for bombesin have been observed in prevertebral sympathetic ganglia of the rat and guinea-pig. The distribution of bombesin immunoreactive fibres was compared with the distribution of the structurally-related peptide substance P. Dense networks of varicose bombesin immunoreactive fibres were observed, and in the rat coeliac ganglion the density exceeded that of the substance P immunoreactive fibres. Extracts of rat and guinea-pig coeliac ganglion contained material cross-reacting in radioimmunoassays for bombesin tetradecapeptide. Similar concentrations of bombesin and substance P were found in the guinea-pig ganglion, whereas in the rat the concentration of bombesin was about 20 times as high as that of substance P. Two molecular forms of immunoreactive bombesin were identified, neither of which corresponded exactly to synthetic bombesin. The two components were also distinguishable from synthetic substance P. A potential role of a bombesin-like peptide in neural pathways between the gut and prevertebral ganglia is suggested.     

成人腹腔神经节的形态观察

目的观察成人腹腔神经节的位置及形态结构,为揭示其功能提供形态学资料。方法取死后24～48h的18具成人尸体的18个腹腔神经节,经石蜡包埋切片,苏木精-伊红、Nissl及Masson染色,观察该神经节的细胞构筑。结果腹腔神经节多位于从腹主动脉发出的腹腔干的两侧,其形态不规则,但轮廓清楚,质地坚实,易与其它结构区别;镜下观察到,该神经节被单层扁平细胞构成的被膜包裹,节内的神经元为多极形,尼氏体丰富,核大圆亮;卫星细胞的形态结构也完整;在节内的细胞间质中含有丰富的胶原纤维。神经节的所有细胞均无溶解现象。结论若能在成年病人死亡后24～48h及时固定,既可确保其腹腔神经节的形态结构完整,又可为神经生物学的教学和科研制作成良好的组织切片标本。