The effect of monocular deprivation on unihemispheric sleep in light and dark incubated/reared domestic chicks

The elastic net (Durbin and Willshaw 1987) can account for the development of both topography and ocular dominance in the mapping from the lateral geniculate nucleus to primary visual cortex (Goodhill and Willshaw 1990). Here it is further shown for this model that (1) the overall pattern of stripes produced is strongly influenced by the shape of the cortex: in particular, stripes with a global order similar to that seen biologically can be produced under appropriate conditions, and (2) the observed changes in stripe width associated with monocular deprivation are reproduced in the model.

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Trypanosoma ontarioensis n.sp. and T. paddae from Corvus brachyrhynchos brachyrhynchos in Ontario, Canada, with notes on the biology of T. ontarioensis n.sp.

Canadian Journal of Zoology ◽

10.1139/z82-269 ◽

1982 ◽

Vol 60 (9) ◽

pp. 2107-2115 ◽

Cited By ~ 10

Author(s):

Patrick T. K. Woo ◽

Cheryl M. Bartlett

Keyword(s):

Agar Medium ◽

Gallus Domesticus ◽

Blood Agar ◽

Melopsittacus Undulatus ◽

Ruffed Grouse ◽

Bonasa Umbellus ◽

Southern Ontario ◽

Corvus Brachyrhynchos ◽

Domestic Chicks ◽

Serinus Canarius

Two morphologically distinct trypanosomes (Trypanosoma ontarioensis n.sp. and Trypanosoma paddae) were found by the haematocrit centrifuge technique in the blood of 53% (64 of 121) of Corvus brachyrhynchos brachyrhynchos wintering in southern Ontario. Trypanosoma ontarioensis n.sp. is a small trypanosome with subterminal kinetoplast. It is monomorphic and not host specific. It was readily cultured in diphasic blood-agar medium. Two-week cultures were infective and contained dividing sphaeromastigotes, epimastigotes, and trypomastigotes. Blood trypomastigotes were detected in low numbers in the blood of inoculated birds (Corvus brachyrhynchos brachyrhynchos, Bonasa umbellus, Gallus domesticus, Melopsittacus undulatus, and Serinus canarius) at 28 and 48 days postinfection. The crows, ruffed grouse, and domestic chicks were laboratory raised while the budgerigars and canaries were from pet stores. One canary that was further examined at 180, 360, 540, 730, and 910 days postinfection still had detectable numbers of trypanosomes in its blood.

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Daytime micro-naps in a nocturnal migrant: an EEG analysis

Biology Letters ◽

10.1098/rsbl.2008.0405 ◽

2008 ◽

Vol 5 (1) ◽

pp. 77-80 ◽

Cited By ~ 27

Author(s):

T Fuchs ◽

D Maury ◽

F.R Moore ◽

V.P Bingman

Keyword(s):

Brain Activity ◽

Sleep Loss ◽

Eeg Analysis ◽

Observable Effect ◽

Brain Response ◽

Night Time ◽

Avian Migration ◽

Unihemispheric Sleep ◽

Daytime Behaviour ◽

Behavioural Evidence

Many species of typically diurnal songbirds experience sleep loss during the migratory seasons owing to their nocturnal migrations. However, despite substantial loss of sleep, nocturnally migrating songbirds continue to function normally with no observable effect on their behaviour. It is unclear if and how avian migrants compensate for sleep loss. Recent behavioural evidence suggests that some species may compensate for lost night-time sleep with short, uni- and bilateral ‘micro-naps’ during the day. We provide electrophysiological evidence that short episodes of sleep-like daytime behaviour (approx. 12 s) are accompanied by sleep-like changes in brain activity in an avian migrant. Furthermore, we present evidence that part of this physiological brain response manifests itself as unihemispheric sleep, a state during which one brain hemisphere is asleep while the other hemisphere remains essentially awake. Episodes of daytime sleep may represent a potent adaptation to the challenges of avian migration and offer a plausible explanation for the resilience to sleep loss in nocturnal migrants.

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