Ultrastructure of neurons of nucleus preopticus and pars lateralis of the nucleus lateralis tuberis in Gambusia (Teleosta poeciliidae)]

The nucleus preopticus (NPO) and the pars lateralis of the nucleus lateralis tuberis (NLT) have been examined at the ultrastructural level. In the NPO two types of large neurons occur, both containing 140-150 nm secretory granules. The pars lateralis of the NLT contains only one cell type with similar granules. Both of these nuclei may be the source of type A fibres innervating the gonadotropic cells of Gambusia.     

Autoradiographic analysis of the primary visual projections of a diurnal predator (Buteo buteo L.)]

Radioautographic analysis of the optic system of a Common Buzzard (Buteo buteo L.) show hypothalamic (Meier's areas 1, 2 and 3), thalamic (nuclei lateralis anterior, geniculatus lateralis ventralis, dorsolateralis anterior), pretactal (nuclei geniculatus lateralis pretectalis--or Kuhlenbeck's geniculatus lateralis dorsalis--superficialis synencephali, griseus tectalis and area pretectalis), tegmental (nucleus ectomammillaris) and tectal visual projections. A general survey of Common Buzzard optic structures suggest a certain preponderancy of tectofugal system on thalamofugal system. Centrifugal visual system is reduced.     

Organization of the mammalian red nucleus and its interconnections with the cerebellum.

The red nucleus in monkeys and rats consists of a magnocellular, rubrospinal portion which receives its cerebellar information from the nucleus interpositus, and a parvocellular, rubroolivary portion which receives cerebellar afferents from the nucleus lateralis. Distinct interpositorubrospinal and dentatorubroolivary projections are therefore common to these 2 species.     

Organization of the mammalian red nucleus and its interconnections with the cerebellum

Summary The red nucleus in monkeys and rats consists of a magnocellular, rubrospinal portion which receives its cerebellar information from the nucleus interpositus, and a parvocellular, rubroolivary portion which receives cerebellar afferents from the nucleus lateralis. Distinct interpositorubrospinal and dentatorubroolivary projections are therefore common to these 2 species.     

Visually guided movement in the cat: difference in the effects of a bilateral lesion of the thalamic nucleus ventralis lateralis performed either before or after training]

Bilatéral lesions of the thalamic nucleus ventralis lateralis were performed in cats, either after [1] or before [2] training to reach a moving target with the forepaw. In situation [1], lesions were ineffective; in situation [2] the animal never reached normal scores. VL thus seems to be essential only in the acquisition phase of the tested visuomotor performance.     

The nucleus lateralis tuberis in the fresh water teleost,Clarias batrachus linn

Zusammenfassung Nachweis, dass die Aktivität der Zellen des Nucleus lateralis bei Fischen, während der Ruhe- und Laichzeit untersucht, eine zyklische ist. Starke Granulation im Nucleus lateralis und Nucleus praeopticus wurde bei einem 21 Tage alten, kastrierten Fisch beobachtet: Granulationsschwund nach Injektion von Testosteronpropionat und Östradiol-dipropionat (Gesamtdosis 5 mg).

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The investigation was supported by a grant from the Ford Foundation, New-Delhi.     

Tele-electromyography of various quadriceps femoris muscle bundles during locomotion in a Madagascar lemur (Lemur fulvus)]

The vastus lateralis muscle is of primary importance in leaping inasmuch as it initiates the jumps; on the contrary the activity of the vastus intermedius does not increase during jumping, but it is the only one to be active in quadrupedal resting postures.     

Increase in muscle fibres in the lateralis muscle (white portion) of Mugilidae (Pisces,Teleostei)

Summary A cycle of postlarval growth is described in the white portion of the lateralis muscle of Mugilidae. The cycle was identified histochemically by the myosin-ATPase reaction.This work was supported by a CNR grant (Oceanografia e fondi marini project).     

Muscle lipofuscin content and satellite cell volume is increased after high altitude exposure in humans

Muscle ultrastructural changes during a typical expedition to the Himalayas were analyzed by taking muscle biopsies from seven climbers before and after their sojourn at high altitude (over 5000 m for 8 weeks). M. vastus lateralis samples were analyzed morphometrically from electron micrographs. A quantitative evaluation was made of lipofuscin, satellite cells and myonuclei. Significant increases of the volume densities of lipofuscin (+ 235%) and satellite cells (+ 215%) were observed.     

Muscle lipofuscin content and satellite cell volume is increased after high altitude exposure in humans

Summary Muscle ultrastructural changes during a typical expedition to the Himalayas were analyzed by taking muscle biopsies from seven climbers before and after their sojourn at high altitude (over 5000 m for 8 weeks). M. vastus lateralis samples were analyzed morphometrically from electron micrographs. A quantitative evaluation was made of lipofuscin, satellite cells and myonuclei. Significant increases of the volume densities of lipofuscin (+235%) and satellite cells (+215%) were observed.     

Location of allatostatic centers in the pars lateralis regions of the brain of the Colorado potato beetle

Summary Selective lesions in the pars intercerebralis and pars lateralis areas of the brain of the adult Colorado potato beetle were produced by radiofrequency cautery. The effect of these lesions on the corpus allatum activity, determined by the short-term in vitro radiochemical assay, revealed that gland inhibitory centers are located in the pars lateralis.     

Descending pathways with monosynaptic action on motoneurones

Zusammenfassung Motoneuronen, sowohl zu Streckwie Beugemuskeln, werden von absteigenden Bahnen des Rückenmarkes supraspinalen Ursprungs monosynaptisch beeinflusst. Es konnte gezeigt werden, dass die Wirkung an den Motoneuronen der Streckmuskeln aus dem Nucleus vestibularis lateralis (Deiters) stammt.     

La teneur du noyau cellulaire en acide désoxyribonucléique à travers les organes,les individus et les espèces animales

Summary Techniques are described for the isolation of nuclei from animals cells and for the determination of the desoxyribonucleic acid content for each nucleus. These techniques have already been used in order to study a few mammalian species. From the first results (especially in calf, ox and bull), it seems to appear that the nucleus of the somatic cells contains constantly the same amount of desoxyribonucleic acid, whatever tissue and animal we studied within the same species; and this amount is just the double of that of the haploid cells (spermatozoa) in the same animal. This result constitutes a strong argument, from the analytical point of view, for the theory according to which the desoxyribonucleic acid is considered to be the substrate of the hereditary characters of the species.     

Cytological evidence on the ability of the nucleolus organizing regions to assemble pre-existing nucleolar material

The treatment of Vicia faba root tips with 5-azacytidine caused unequal allotment of the chromosomes; after one cell cycle, a pair of daughter nuclei was produced, one of which carried the nucleolus organizing regions (NORs) and the other of which lacked them. The pre-existing nucleolar material brought into the NOR-carrying daughter nucleus by the chromosomes disappeared concurrently with the appearance of the new nucleoli, whereas in another daughter nucleus without the NOR a number of small nucleolus-like bodies became visible at random positions. These findings suggest that in addition to ribosomal RNA synthesis the NOR has another role in cells; to stimulate the pre-existing nucleolar material to assemble at the NOR itself.     

Neurosecretory system and storage of paraldehyde fuchsin positive neurosecretory material in the dorsal aorta in an earwig,Anisolabis annulipes Lucas (Dermaptera: Labiduridae)

Summary Each of the 2 groups of medial neurosecretory cells has 10–12 A and 2–3 B-cells. Each pars intercerebralis lateralis has 3–4 B-cells only. The 2 nervi corporis cardiaci I (NccI) join with the lateral wall of the aorta and Ncc II terminate in corpora cardiaca (Cc). Only 1 corpus allatum is present. The paraldehyde fuchsin positive neurosecretory material is stored in the dorsal aorta and not in the Cc which indicates the neurohaemal nature of the aorta.We are grateful to Prof. U.S. Srivastava for providing laboratory facilities and S.C.S.T. Uttar Pradesh for financial assistance.     

Cytological evidence on the ability of the nucleolus organizing regions to assemble pre-existing nucleolar material

Summary The treatment ofVicia faba root tips with 5-azacytidine caused unequal allotment of the chromosomes; after one cell cycle, a pair of daughter nuclei was produced, one of which carried the nucleolus organizing regions (NORs) and the other of which lacked them. The pre-existing nucleolar material brought into the NOR-carrying daughter nucleus by the chromosomes disappeared concurrently with the appearance of the new nucleoli, whereas in another daughter nucleus without the NOR a number of small nucleolus-like bodies became visible at random positions. These findings suggest that in addition to ribosomal RNA synthesis the NOR has another role in cells; to stimulate the pre-existing nucleolar material to assemble at the NOR itself.     

The site of triglyceride biosynthesis in milk.

THe triglyceride biosynthesis which occurs in freshly secreted goat skim milk can be localized predominantly to large (1-8 mum) pieces of membrane-bounded cytoplasm. These contain the usual cytoplasmic organelles (but no nucleus) plus one or more large lipid droplets.     

Reciprocal connections between substantia nigra and medullary reticular formation in the rat

Summary Electrophysiological analysis shows reciprocal connections between substantia nigra and medullary reticular formation (nucleus reticularis giganto celullaris). The nigro-reticular connection appears to be monosynaptic, as shown by antidromic activation, and comprises an ipsi and a contralateral component. Its effect is mainly inhibitory. The reticulonigral component produces mainly excitatory effects and includes fibres from nucleus giganto celullaris and nucleus parvocelullaris in the medullary reticular formation.This work was aided by a grant from CONICIT (projecto 31.26.S1-0412).     

Dopamine-β-hydroxylase activity in stroke-prone spontaneously hypertensive rats

Summary Dopamine--hydroxylase (DBH) activity was higher in the serum, the mesenteric artery and the cerebral cortex of 4-week-old stroke-prone spontaneously hypertensive rats (SHRSP), and lower in the nucleus tractus solitarii than it was in spontaneously hypertensive rats (SHR).The authors wish to thank Prof. Masao Sano (Nagoya University) for his aid in dissecting the nucleus tractus solitarii and the locus coeruleus.