Sleep-wakefulness patterns in the aged cat

Bowersox, S. Scott; Baker, Theodore L.; Dement, William C.

doi:10.1016/0013-4694(84)90110-x

Cited by 28 publications

(12 citation statements)

References 27 publications

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“…Similar age-related changes in the sleep-wake pattern have also been described by other experimenters in different rat strains (19,20) and even in other species such as the cat (25,26) and the mouse (27). The finding of an age-related reduction of SWS time is not in agreement with the results of our earlier experiment, carried out in only six young adult and five 22-month-old Wistar rats.…”

Section: Discussioncontrasting

confidence: 52%

Effects of Aging and Housing in an Enriched Environment on Sleep-Wake Patterns in Rats

Gool¹,

Mirmiran²

1986

Sleep

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Summary: The effects of aging and housing in an enriched environment were assessed in young adult (4-7 months) and old (27-31 months) male Brown Norway rats by conducting 24-h sleep-wake recordings. Comparison of recordings made in rats of different ages, housed in a standard laboratory environment, revealed a reduction of the time spent in slow wave and desynchronized sleep during the light period in the old rats. Furthermore in the old rats, sleep was more fragmented and the amplitude of the circadian sleep-wake rhythm was reduced. In both age groups, housing in an enriched environment resulted in an increase of the time spent in slow wave and de synchronized sleep during the light period. Old "enriched" rats showed an additional alleviation of the senescence-related shortening of sleep cycles and de synchronized sleep epochs. The reduction of the circadian sleep-wake amplitude observed in old age was, however, not affected by the differential housing period. It is concluded that the similarity of the changes in sleep pattern in young and old rats after increased environmental complexity may reflect a preserved capacity of the senescent nervous system to adapt to environmental changes. Key Words: Sleep-Aging-Enriched environment-Circadian sleep-wake rhythm-Rat.Changes in sleep-wake patterns appear to be one of the hallmarks of biological aging (1). Sleep recordings in humans, as well as in various animal species, during senescence reveal a fragmentation and overall reduction of sleep, as well as changes in the circadian organization of the sleep-wake cycle [cf. Miles and Dement (1), Ingram et al. (2) for review]. In a previous experiment, we found an age-related increase in time spent awake at the expense of desynchronized sleep (DS) time in Wistar rats (3). The biological relevance of these findings can perhaps best be understood in the light of hypotheses that attribute an adaptive role to sleep in general, and to DS in particular (4,5). These hypotheses have been corroborated by the results of experiments in which housing in an enriched environment resulted in an increase in total sleep time (TST) (6-9) and/or in DS time (10) in developing and adult rats. Housing in an enriched

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Section: Discussioncontrasting

confidence: 52%

Effects of Aging and Housing in an Enriched Environment on Sleep-Wake Patterns in Rats

Gool¹,

Mirmiran²

1986

Sleep

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“…Table 2 also indicates that RHT projections in guinea pigs and domestic cats are confined to the SCN (Cassone et al, 1988). However, substantial disagreement exists as to the circadian phase preference of these two species (Bowersox et al, 1984; Jilge, 1985; Kuwabara et al, 1986; Tobler and Scherschlicht, 1990; Tobler et al, 1993; Akita et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

Distinct retinohypothalamic innervation patterns predict the developmental emergence of species‐typical circadian phase preference in nocturnal Norway rats and diurnal nile grass rats

Todd

Gall

Weiner

et al. 2012

J of Comparative Neurology

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How does the brain develop differently to support nocturnality in some mammals, but diurnality in others? To answer this, one might look to the suprachiasmatic nucleus (SCN), which is entrained by light via the retinohypothalamic tract (RHT). However, because the SCN is more active during the day in all mammals studied thus far, it alone cannot determine circadian phase preference. In adult Norway rats (Rattus norvegicus), which are nocturnal, the RHT also projects to the ventral subparaventricular zone (vSPVZ), an adjacent region that expresses an in-phase pattern of SCN-vSPVZ neuronal activity. In contrast, in adult Nile grass rats (Arvicanthis niloticus), which are diurnal, an anti-phase pattern of SCN-vSPVZ neuronal activity is expressed. We hypothesized that these species differences result in part from a weak or absent RHT-to-vSPVZ projection in grass rats. Here, using a developmental comparative approach, we assessed species differences in behavior, hypothalamic activity, and RHT anatomy. We report that a robust retina-to-vSPVZ projection develops in Norway rats around the end of the second postnatal week when nocturnal wakefulness and the in-phase pattern of neuronal activity emerge. In grass rats, however, such a projection does not develop and the emergence of the anti-phase pattern during the second postnatal week is accompanied by increased diurnal wakefulness. When considered within the context of previously published reports on RHT projections in a variety of species, the current findings suggest that how and when the retina connects to the hypothalamus differentially shapes brain and behavior to produce animals that occupy opposing temporal niches.

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“…visual inspection of sleep EEG recordings from young and old animals disclosed both ageand gender-related reductions in slow-wave activity (10,11). The current investigation used a more quantitative analytical approach (period-amplitude analysis) to confirm and extend these earlier observations.…”

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confidence: 99%

Electroencephalogram During Sleep in the Cat: Age Effects on Slow-Wave Activity

Bowersox

Floyd

Dement

1984

Sleep

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Summary:In humans there is a substantial decline in NREM electroencephalographic (EEG) slow-wave activity with advancing age. The present findings show that similar age-related EEG changes occur in the cat. Slow-wave (0.5-4.0 Hz) EEG activity during NREM sleep was compared in six young adult (2-4 years) and six aged (10-12 years) cats of either sex. Computer measures of slow-wave incidence and amplitude disclosed significant age-and gender-related differences. Although old male and female animals were of comparable age, only males showed significant EEG alterations. These consisted of an attenuation of slow-wave amplitude over posterolateral cortex and reductions in both the incidence and amplitude of slow-wave activity over sensorimotor cortex. Key Words: Aging-Among the electroencephalographic (EEG) changes commonly associated with advancing age in humans is a marked decline in the incidence and amplitude of slow-wave (0.5-3.0 Hz) activity during NREM sleep. This decline, as documented by both visual (1-6) and computer-assisted (5,7-9) EEG scoring techniques, is a consistent feature of the aging process. It begins in adolescence and continues across the lifespan, often resulting by the eighth decade in the complete loss of 0.5-3.0 Hz wave forms (4).Although it is well established that EEG slow-wave activity is attenuated in old age, the contributions of intracerebral and extracerebral factors to this process have not been well delineated. Intracerebral factors, including the loss of neuropil and dendritic ramifications, undoubtedly playa key role. However, because EEG potentials are conventionally recorded from scalp leads, extracerebral factors such as changes in brain volume, thickening of the meninges, and alterations in skull and scalp conductivity-all of which distance and insulate electrodes from the cortical surface-are also probably implicated. Unfortunately, usual methodological constraints make it difficult to assess the respective contributions of these factors to EEG changes in human subjects. However, this opportunity is afforded in animal studies where recording electrodes can be placed directly on the cortical surface.The principal aim of the present investigation was to assess the extent to which EEG spectral characteristics change as a function of age in the laboratory cat. In an earlier study

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Sleep-wakefulness patterns in the aged cat

Cited by 28 publications

References 27 publications

Effects of Aging and Housing in an Enriched Environment on Sleep-Wake Patterns in Rats

Effects of Aging and Housing in an Enriched Environment on Sleep-Wake Patterns in Rats

Distinct retinohypothalamic innervation patterns predict the developmental emergence of species‐typical circadian phase preference in nocturnal Norway rats and diurnal nile grass rats

Electroencephalogram During Sleep in the Cat: Age Effects on Slow-Wave Activity

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