Background The authors investigated whether the sedative, or hypnotic, action of general anesthetic dexmedetomidine (a selective alpha -adrenoceptor agonist) activates endogenous nonrapid eye movement (NREM) sleep-promoting pathways. Methods c-Fos expression in brain nuclei was assessed rats using immunohistochemistry and hybridization. Next, perturbed these pathways (1) discrete lesions induced by ibotenic acid, (2) local systemic administration gamma-aminobutyric acid receptor type A (GABA...

The "ascending reticular activating system" theory proposed that neurons in the upper brainstem formation projected to forebrain targets promoted wakefulness. More recent formulations have emphasized most at pontomesencephalic junction participate these pathways are actually monoaminergic and cholinergic cell groups. However, cell-specific lesions of groups never been able reproduce deep coma seen after acute paramedian midbrain transect ascending axons caudal level. To determine whether...

Recent evidence suggests that dopamine plays an important role in arousal, but the location of dopaminergic neurons may regulate arousal remains unclear. It is sometimes assumed ventral tegmental area project to prefrontal cortex and striatum state arousal; however, firing these does not correlate with overall levels behavioral wakefulness. We identified wake-active by combining immunohistochemical staining for Fos tyrosine hydroxylase (TH) awake sleeping rats. Approximately 50%...

We found previously that damage to a cluster of sleep-active neurons (Fos-positive during sleep) in the ventrolateral preoptic nucleus (VLPO) decreases non-rapid eye movement (NREM) sleep rats, whereas injury cells extending dorsally and medially from VLPO (the extended VLPO) diminishes REM sleep. These results led us examine whether are activated connectivity these with pontine sites implicated producing sleep: laterodorsal tegmental (LDT), dorsal raphe (DRN), locus ceruleus (LC). After...

Background Previous work has suggested, but not demonstrated directly, a critical role for both glutamatergic and GABAergic neurons of the pontine tegmentum in regulation rapid eye movement (REM) sleep. Methodology/Principal Findings To determine vivo roles these fast-acting neurotransmitters putative REM circuits, we injected an adeno-associated viral vector expressing Cre recombinase (AAV-Cre) into mice harboring lox-P modified alleles either vesicular glutamate transporter 2 (VGLUT2) or...

Considerable data support a role for glycinergic ventromedial medulla neurons in the mediation of postsynaptic inhibition spinal motoneurons necessary motor atonia rapid-eye movement (REM) sleep cats. These are, however, difficult to reconcile with fact that large lesions rostral ventral do not result loss REM rats. In present study, we sought clarify which medullary networks rodents are responsible by retrogradely tracing inputs horn from medulla, ablating these sources determine their...

The mesencephalic (or midbrain) locomotor region (MLR) was first described in 1966 by Shik and colleagues, who demonstrated that electrical stimulation of this induced locomotion decerebrate (intercollicular transection) cats. pedunculopontine tegmental nucleus (PPT) cholinergic neurons midbrain extrapyramidal area (MEA) have been suggested to form the neuroanatomical basis for MLR, but direct evidence role these structures behavior has lacking. Here, we tested hypothesis MLR is composed...

Interaction between the basal ganglia and cortex plays a critical role in range of behaviors. Output from to is thought be relayed through thalamus, but an intriguing alternative that may directly project communicate with cortex. We explored efferent projection globus pallidus externa (GPe), key hub system, rats mice. Anterograde retrograde tracing revealed projections frontal premotor cortex, especially deep projecting layers, originating GPe neurons receive axonal inputs dorsal striatum....

Activation of the parabrachial nucleus (PB) in brainstem induced wakefulness rats, suggesting which is an important that controls arousal. However, sub-regions PB regulating sleep-wake cycle still unclear. Here, we employ chemogenetics and optogenetics strategies find activation medial part (MPB), but not lateral part, induces continuous for 10 h without sleep rebound neither amount nor power spectra. Optogenetic glutamatergic MPB neurons sleeping rats immediately wake mediated by basal...

Abstract Anesthesia, slow‐wave sleep, syncope, concussion and reversible coma are behavioral states characterized by loss of consciousness, cortical electroencephalogram, motor sensory suppression. We identified a focal area in the rat brainstem, mesopontine tegmental anesthesia (MPTA), at which microinjection pentobarbital other GABA A receptor (GABA ‐R) agonists reversibly induced an anesthesia‐like state. This effect was attenuated local pre‐treatment with ‐R antagonist bicuculline. Using...

Early in the twentieth century, von Economo provided first evidence linking hypothalamus with sleep-wake behavior. His studies concluded that anterior was associated sleep, whereas posterior waking. In decades following these observations, a wealth of research has shown an elaborate circuitry comprising number brain regions, cell types, and extracellular messengers underlies this review, we discuss data generated past 10 years highlight role behavior control. particular, will focus on...

Background Rapid eye movement sleep (REMS) is characterized by activation of the cortical and hippocampal electroencephalogram (EEG) atonia non-respiratory muscles with superimposed phasic activity or twitching, particularly cranial such as those eye, tongue, face jaw. While a characteristic feature REMS, neural substrates driving this remain unresolved. Here we investigated circuits underlying masseter (jaw) during REMS. The trigeminal motor nucleus (Mo5), which controls function, receives...

Considerable electrophysiological and pharmacological evidence has long suggested an important role for acetylcholine in the regulation of rapid-eye-movement (REM) sleep. For example, injection cholinergic agonist carbachol into dorsomedial pons produces REM sleep-like state with muscle atonia cortical activation, both which are cardinal features Located within this region is sublaterodorsal nucleus (SLD), a structure thought to be necessary sufficient generating sleep atonia. Subsets...

Spontaneous synchronization over large networks is ubiquitous in nature, ranging from inanimate to biological systems. In the human brain, neuronal and de-synchronization occur during sleep, with greatest degree of slow wave sleep (SWS). The current classification schema based on electroencephalography provides common criteria for clinicians researchers describe stages non-rapid eye movement (NREM) as well rapid (REM) sleep. These stage classifications have been convenient heuristic...

Rapid eye movement (REM) sleep is a distinct behavioral state characterized by an activated cortical and hippocampal electroencephalogram (EEG) concurrent muscle atonia. Research conducted over the past 50 years has revealed neuronal circuits responsible for generation maintenance of REM sleep, as well pathways involved in generating cardinal signs such activation The appear to involve widespread network pons medulla. caudal laterodorsal tegmental nucleus (cLDT) sublaterodorsal (SLD) within...

Abstract Microinjection of pentobarbital and GABA A ‐receptor agonists into a brainstem region we have called the mesopontine tegmental anesthesia area (MPTA; Devor Zalkind [ 2001 ] Pain 94:101–112) induces general anesthesia‐like state. As in systemic anesthesia, rats show loss righting reflex, atonia, nonresponsiveness to noxious stimuli, apparent consciousness. agonist anesthetics acting on MPTA might suppress movement by engaging endogenous motor regulatory systems previously identified...