Simultaneous invasive and non-invasive recordings in humans: A novel Rosetta stone for deciphering brain activity.

Simultaneous noninvasive and invasive electrophysiological recordings provide a unique opportunity to achieve a comprehensive understanding of human brain activity, much like a Rosetta stone for human neuroscience. In this review we focus on the increasingly-used powerful combination of intracranial electroencephalography (iEEG) with scalp electroencephalography (EEG) or magnetoencephalography (MEG). We first provide practical insight on how to achieve these technically challenging recordings.

Sleep, but not febrile responses of Fisher 344 rats to immune challenge are affected by aging.

Sleep is altered in response to infection and immune challenge in humans and non-human animals. Although there are changes in sleep and facets of immune function with aging, sleep responses of aged subjects to immune challenge have received little, if any attention. To test the hypothesis that aging affects sleep responses to immune challenge, intracerebroventricular injections of interleukin 1 (IL-1) were given to young and aged rats and subsequent sleep-wake behavior was determined.

Interleukin-1beta enhances non-rapid eye movement sleep when microinjected into the dorsal raphe nucleus and inhibits serotonergic neurons in vitro.

Interleukin-1 (IL-1) and IL-1 receptors are constitutively expressed in normal brain. IL-1 increases non-rapid eye movements (NREM) sleep in several animal species, an effect mediated in part by interactions with the serotonergic system. The site(s) in brain at which interactions between IL-1 and the serotonergic system increase NREM sleep remain to be identified.

Spatial buffering during slow and paroxysmal sleep oscillations in cortical networks of glial cells in vivo.

The ability of neuroglia to buffer local increases of extracellular K(+) has been known from in vitro studies. This property may confer on these cells an active role in the modulation and spreading of cortical oscillatory activities. We addressed the question of the spatial buffering in vivo by performing single and double intraglial recordings, together with measures of the extracellular K(+) and Ca(2+) concentrations ([K(+)](out) and [Ca(2+)](out)) in the cerebral cortex of cats under ketamine and xylazine anesthesia during patterns of slow sleep oscillations and spike-wave seizures.