Local functional state differences between rat cortical columns

Rector, David M.; Topchiy, Irina; Carter, Kathleen M.; Rojas, Manuel J.

doi:10.1016/j.brainres.2005.04.002

Cited by 136 publications

(136 citation statements)

References 84 publications

Supporting

Mentioning

128

Contrasting

Unclassified

Order By: Relevance

“…For example, intracranial recordings in epileptic patients have shown that the slow waves and spindles of NREM sleep often occur in some cortical areas but not in others (54) and frequently involve only small groups of neurons (55,56), a finding that was confirmed in rats (15). Recordings of evoked responses in the rat barrel cortex after whisker stimulation also suggest the possible occurrence of "local wake during sleep": responses sometimes appear sleeplike in one cortical column but wake-like in another (57). Finally, by using intracortical multiarray recordings, we recently found that, when rats stay awake longer than usual to explore and learn, small groups of cortical neurons can go offline while the rest of the brain is awake (15), a phenomenon called "local sleep during wake."…”

Section: Discussionmentioning

confidence: 97%

Sleep- and wake-dependent changes in neuronal activity and reactivity demonstrated in fly neurons using in vivo calcium imaging

Bushey

Tononi

Cirelli

2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Sleep in Drosophila shares many features with mammalian sleep, but it remains unknown whether spontaneous and evoked activity of individual neurons change with the sleep/wake cycle in flies as they do in mammals. Here we used calcium imaging to assess how the Kenyon cells in the fly mushroom bodies change their activity and reactivity to stimuli during sleep, wake, and after short or long sleep deprivation. As before, sleep was defined as a period of immobility of >5 min associated with a reduced behavioral response to a stimulus. We found that calcium levels in Kenyon cells decline when flies fall asleep and increase when they wake up. Moreover, calcium transients in response to two different stimuli are larger in awake flies than in sleeping flies. The activity of Kenyon cells is also affected by sleep/wake history: in awake flies, more cells are spontaneously active and responding to stimuli if the last several hours (5-8 h) before imaging were spent awake rather than asleep. By contrast, long wake (≥29 h) reduces both baseline and evoked neural activity and decreases the ability of neurons to respond consistently to the same repeated stimulus. The latter finding may underlie some of the negative effects of sleep deprivation on cognitive performance and is consistent with the occurrence of local sleep during wake as described in behaving rats. Thus, calcium imaging uncovers new similarities between fly and mammalian sleep: fly neurons are more active and reactive in wake than in sleep, and their activity tracks sleep/wake history.T he fundamental features that characterize mammalian sleep also define Drosophila melanogaster sleep (1-3). Most crucially, in both flies and mammals, sleep is distinguished from simple rest (quiet wake) by an increased arousal threshold, i.e., a reduced ability to respond to external stimuli. Moreover, in flies and mammals sleep is controlled homeostatically by the duration as well by the intensity of prior wake, suggesting basic similarities in the mechanisms of sleep regulation across species. Thus, in flies both sleep deprivation and a rich learning experience lead to a sleep rebound characterized by overall increased sleep time, increased arousal threshold, and longer sleep episodes (4-6). As in mammals, overall neuronal activity in flies is also high during wake and low during sleep (6-8). Specifically, a seminal study using local field potential (LFP) recordings from the Drosophila medial protocerebrum found high spike-like potentials that disappeared after the block of synaptic transmission in the mushroom bodies (MBs) (7). This high spike activity was present when flies were moving or had been quiescent for only a few seconds, but disappeared with sleep (i.e., after periods of immobility >5 min), when the overall LFP power in all frequencies also decreased by ∼60% (7). The study concluded that neural activity in the sleeping fly brain, or at least in a central region spanning the MBs, resembles that seen in mammals in several brainstem cell groups including noradrenergic ne...

show abstract

Section: Discussionmentioning

confidence: 97%

Sleep- and wake-dependent changes in neuronal activity and reactivity demonstrated in fly neurons using in vivo calcium imaging

Bushey

Tononi

Cirelli

2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…EEG SWA is posited to be indicative of sleep intensity (Borbely and Tobler 1989) because it is enhanced during the deep sleep following sleep deprivation (Pappenheimer et al, 1975). Microinjection of TNFα onto the surface of the SSctx also increases the amplitude of surface evoked potentials induced by whisker stimulation (Churchill et al, 2005a) in a fashion similar to the increase in surfaceevoked potentials during quiet sleep (Rector et al 2005), suggesting that increases in extracellular TNF can alter the physiological responses to neural stimulation. Such enhanced potentials are characteristic of a cortical column sleep-like state (Rector et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

TNFα siRNA reduces brain TNF and EEG delta wave activity in rats

et al. 2007

View full text Add to dashboard Cite

Tumor necrosis factor alpha (TNFα) is a pleiotropic cytokine with several CNS physiological and pathophysiological actions including sleep, memory, thermal and appetite regulation. Short interfering RNAs (siRNA) targeting TNFα were incubated with cortical cell cultures and microinjected into the primary somatosensory cortex (SSctx) of rats. The TNFα siRNA treatment specifically reduced TNFα mRNA by 45% in vitro without affecting interleukin-6 or gluR1-4 mRNA levels. In vivo the TNFα siRNAα reduced TNFα mRNA, interleukin-6 mRNA and gluR1 mRNA levels compared to treatment with a scrambled control siRNA. After in vivo microinjection, the density of TNFα-immunoreactive cells in layer V of the SSctx was also reduced. Electroencephalogram (EEG) delta wave power was decreased on days 2 and 3 on the side of the brain that received the TNFα siRNA microinjection relative to the side receiving the control siRNA. These findings support the hypothesis that TNFα siRNA attenuates TNFα mRNA and TNFα protein in the rat cortex and that those reductions reduce cortical EEG delta power. Results also are consistent with the notion that TNFα is involved in CNS physiology including sleep regulation.

show abstract

“…For instance, the probability of a particular column being in the sleep-like state depends on the prior duration of its wake-like state. 60 If the whole animal is asleep, most cortical columns are in the sleep-like state, and conversely, if the animal is awake, most columns are in wake-like state. Further, enhanced afferent activity (e.g., by repeatedly twitching a single whisker), as well as local micro-injection of TNF, induce columns to switch to the sleep-like state.…”

Section: State Oscillations In Local Neuronal Networkmentioning

confidence: 99%