Unit responses of the lateral geniculate body to light flashes during wakefulness and synchronized sleep

Riassunto Registrazione microelettrodica eseguita in gatti pretrigeminali dalla parte dorsale del nucleo geniculato laterale (LGB). Si dimostra che le cellule del LGB hanno una risposta maggiore in frequenza a brevi lampi di luce durante la veglia anzichè durante il sonno sincronizzato.     

Corticospinal influences on primary afferents during sleep and wakefulness

Riassunto Nel sonno desincronizzato si osserva un aumento della scarica piramidale originante dalle aree somato-sensoriali della corteccia in corrispondenza dei REM. Queste scariche piramidali depolarizzano le fibre afferenti primarie della via riflessa flessoria e verosimilmente contribuiscono alla depressione fasica dei riflessi polisinaptici che si manifesta durante i REM.

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This investigation was supported by PHS research grant NB-02990-04 from the National Institute of the Neurological Diseases and Blindness, N.I.H., Public Health Service (USA).     

Spinal reflexes in normal unrestrained cats during sleep and wakefulness

Riassunto I riflessi spinali monosinaptico (MR) e polisinaptico (PR) variano in ampiezza ma sono sempre presenti nella veglia e sonno leggero. Nel sonno profondo il MR e PR sono aboliti; la soglia del MR è innalzata e la potenziazione post-tetanica abolita.     

The effects of reticular stimulation on digastric reflex activity during sleep and wakefulness

Résumé La stimulation électrique de la formation réticulaire mésencéphalique fut appliquée 0–20 msec avant l'induction du réflexe digastrique chez des chats libres. Le reflexe digastrique fut induit par stimulation électrique du nerf dentaire inférieur. La stimulation réticulaire eut pour résultat l'inhibition de ce réflexe pendant la veille, le sommeil tranquille et le sommeil actif.     

Cyclic variation in the amplitude of a brain stem reflex during sleep and wakefulness

Zusammenfassung In frei beweglichen Katzen wurden Veränderungen des Reflexes zum Musculus massetericus während des Schlafes und im Wachzustand untersucht. Eine graduelle Abnahme der Amplitude des Reflexes wurde beobachtet, wenn die Tiere vom Wachzustand über eine «schläfrige Phase» (drowsy state) in die sogenannte «ruhige Schlafphase» (quiet sleep) gelangten. Während des paradoxalen Schlafes (active sleep) waren die Amplituden der Reflexpotentiale hochgradig herabgesetzt.

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This research was supported by a grant from the USPHS (MH-10083) and by the Veterans Administration.

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This work has received bibliographic aid from the UCLA Brain Information Service which is a part of the National Information Network of the NINDB, and supported under Contract No. PH-43-66-59.     

The activity of neurons in the lateral geniculate body during wakefulness and natural sleep

Résumé On a montré que l'activité neuronique du corps genouillé externe du chat diminue lorsque l'animal passe de l'éveil au sommeil à ondes lentes, et augmente lorsque l'animal passe au sommeil à ondes rapides de bas voltage.     

Reflex activity of extensor and flexor muscles following muscular afferent excitation during sleep and wakefulness

Riassunto Nel gatto integro non anestetizzato il riflesso monosinaptico estensorio e il riflesso polisinaptico flessorio subiscono soltanto lievissime, a volte impercettibili, modificazioni nel passaggio dallo stato di veglia al sonno sincronizzato. Per contro, nel sonno profondo desincronizzato si osserva l'abolizione completa del riflesso monosinaptico e un'elevazione della soglia per il riflesso ipsilaterale flessorio. Per stimoli efficaci a produrre nel sonno profondo questa contrazione flessoria si osserva anche una risposta motoria generalizzata, che si accompagna ad una reazione di risveglio.

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This investigation was supported by PHS research grant B-2990 from the National Institute of Neurological Diseases and Blindness, N.I.H., Public Health Service (U.S.A.).     

Somatic evoked responses in cats during natural sleep

Riassunto Le risposte corticali evocate da stimoli somatici, sia periferici che centrali, aumentano di ampiezza durante il sonno profondo. Tale amplificazione è dovuta, almeno in parte, ad una facilitata trasmissione degli impulsi ascendenti a livello del nucleo ventro-postero-laterale del talamo.

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Part of these results has been presented at a meeting of the Società Italiana di Biologia Sperimentale held in Genova on July 25th 1962.     

Acute physiological responses during blood substitution with colloidal gelatin in conscious rats

The effects of exchange-transfusion with a proprietary gelatin-based plasma volume expander, Haemaccel, have been investigated in conscious, chronically-catheterized rats. No adverse changes in basic cardiovascular or respiratory functions occurred during the procedure although an increase in intravascular fluid sodium but not potassium concentration was observed.     

Acute physiological responses during blood substitution with colloidal gelatin in conscious rats

Summary The effects of exchange-transfusion with a proprietary gelatin-based plasma volume expander, Haemaccel, have been investigated in conscious, chronically-catheterized rats. No adverse changes in basic cardiovascular or respiratory functions occurred during the procedure although an increase in intravascular fluid sodium but not potassium concentration was observed.     

Interdependence between locomotor activity and duration of wakefulness in humans during isolation

Summary Locomotor activity was recorded in 14 subjects who lived singly in an isolation unit for 16 to 88 days. Their free-running circadian rhythms had a mean period of 25.9 h, with individual means in the duration of wakefulness () ranging from 12.1 to 22.9 h. Intraindividually, the hourly means of activity were negatively correlated with to such a degree that the total amount of activity per day remained constant irrespective of large variations in .     

Responsiveness and discrimination during sleep

Résumé La discrimination tonale a été analysée chez des chats dressés pendant l'état de veille à répondre à un son d'une fréuence donnée (son «positif») et à ne pas répondre aux autres fréquences sonores (sons «négatifs»). Pendant la veille, l'efficacité des sons «negatifs» diminue au fur et à mesure que la différence de fréquence avec le son «positif» augmente. Pendant le sommeil lent et de haut voltage, l'efficacité du son «positif» ne change pas ou diminue peu, tandis que celle des sons «négatifs» est réduite: ainsi, le chat endormi possède encore la possibilité de faire des discriminations précises. Pendant la phase «rhombencéphalique» du sommeil, l'efficacité de tous les sons disparaît: on discute la nature de ce manque de réactivité.     

Interdependence between locomotor activity and duration of wakefulness in humans during isolation

Locomotor activity was recorded in 14 subjects who lived singly in an isolation unit for 16 to 88 days. Their free-running circadian rhythms had a mean period of 25.9 h, with individual means in the duration of wakefulness (alpha) ranging from 12.1 to 22.9 h. Intraindividually, the hourly means of activity were negatively correlated with alpha to such a degree that the total amount of activity per 'day' remained constant irrespective of large variations in alpha.     

Experimental dissociation between hippocampal theta activity in wakefulness and hippocampal theta activity in paradoxal sleep in the rat]

The effects of electrolytic lesion of the septum on the theta activity of the dorsal hippocampus were studied in the chronically implanted Rat during wakefulness and paradoxical sleep. The experimental results show that depending on its localization, septal lesion can either: (1) eliminate the wakefulness theta rhythm without suppressing that of paradoxical sleep; (2) eliminate the paradoxical sleep theta rhythm without suppressing that of wakefulness. These results suggest that there are two kinds of theta activity having different anatomophysiological bases and a different functional significance: one associated with wakefulness and the other with paradoxical sleep.