polygraphic-recording-procedure-for-measuring-sleep-in-mice

Polygraphic Recording Procedure for Measuring Sleep in Mice

Recording of the epidural electroencephalogram (EEG) and electromyogram (EMG) in small animals, like mice and rats, has been pivotal to study the ...

university of tsukuba

Escherichia coli proteome chips for detecting protein-protein interactions.

Although recent advances in fluorescence-based technologies, such as protein microarrays, have made it possible to analyse more than 10,000 proteins at once, there is a bottleneck in the step of preparation of large numbers of fluorescently labelled proteins for the comprehensive analysis of protein-protein interactions. Here we describe two independent methods for high-throughput fluorescence-labelling of full-length cDNA products at their C-termini using a reconstituted translation system containing fluorescent puromycin. For the first method, release factor-free systems were used. For the second method, stop codons were excluded from cDNAs by using a common mismatch primer in mutagenic PCR. These methods yielded large numbers of labelled proteins from cDNA sets of various organisms, such as mouse, yeast and Escherichia coli.

High-throughput fluorescence labelling of full-length cDNA products based on a reconstituted translation system.

Adenosine has been proposed to promote sleep through A(1) receptors (A(1)R's) and/or A(2A) receptors in the brain. We previously reported that A(2A) receptors mediate the sleep-promoting effect of prostaglandin D(2), an endogenous sleep-inducing substance, and that activation of these receptors induces sleep and blockade of them by caffeine results in wakefulness. On the other hand, A(1)R has been suggested to increase sleep by inhibition of the cholinergic region of the basal forebrain. However, the role and target sites of A(1)R in sleep-wake regulation remained controversial. In this study, immunohistochemistry revealed that A(1)R was expressed in histaminergic neurons of the rat tuberomammillary nucleus (TMN). In vivo microdialysis showed that the histamine release in the frontal cortex was decreased by microinjection into the TMN of N(6)-cyclopentyladenosine (CPA), an A(1)R agonist, adenosine or coformycin, an inhibitor of adenosine deaminase, which catabolizes adenosine to inosine. Bilateral injection of CPA into the rat TMN significantly increased the amount and the delta power density of non-rapid eye movement (non-REM; NREM) sleep but did not affect REM sleep. CPA-promoted sleep was observed in WT mice but not in KO mice for A(1)R or histamine H(1) receptor, indicating that the NREM sleep promoted by A(1)R-specific agonist depended on the histaminergic system. Furthermore, the bilateral injection of adenosine or coformycin into the rat TMN increased NREM sleep, which was completely abolished by coadministration of 1,3-dimethyl-8-cyclopenthylxanthine, a selective A(1)R antagonist. These results indicate that endogenous adenosine in the TMN suppresses the histaminergic system via A(1)R to promote NREM sleep.

Adenosine in the tuberomammillary nucleus inhibits the histaminergic system via A1 receptors and promotes non-rapid eye movement sleep.

The role of the diffusible messenger nitric oxide (NO) in the regulation of pain transmission is still a debate of matter, pro-nociceptive and/or anti-nociceptive. S-Nitrosylation, the reversible post-translational modification of selective cysteine residues in proteins, has emerged as an important mechanism by which NO acts as a signaling molecule. The occurrence of S-nitrosylation in the spinal cord and its targets that may modulate pain transmission remain unclarified. The "biotin-switch" method and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry were employed for identifying S-nitrosylated proteins.

Involvement of S-nitrosylation of actin in inhibition of neurotransmitter release by nitric oxide.

We found that rubiscolin-6, a δ opioid agonist peptide derived from d-ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), a major protein of green leaves, stimulates food intake after oral administration in mice. We therefore investigated its mechanism.

Orally administered rubiscolin-6, a δ opioid peptide derived from Rubisco, stimulates food intake via leptomeningeal lipocallin-type prostaglandin D synthase in mice.

Narcolepsy is characterized by excessive sleepiness and cataplexy, sudden episodes of muscle weakness during waking that are thought to be an intrusion of rapid eye movement sleep muscle atonia into wakefulness. One of the most striking aspects of cataplexy is that it is often triggered by strong, generally positive emotions, but little is known about the neural pathways through which positive emotions trigger muscle atonia. We hypothesized that the amygdala is functionally important for cataplexy because the amygdala has a role in processing emotional stimuli and it contains neurons that are active during cataplexy. Using anterograde and retrograde tracing in mice, we found that GABAergic neurons in the central nucleus of the amygdala heavily innervate neurons that maintain waking muscle tone such as those in the ventrolateral periaqueductal gray, lateral pontine tegmentum, locus ceruleus, and dorsal raphe. We then found that bilateral, excitotoxic lesions of the amygdala markedly reduced cataplexy in orexin knock-out mice, a model of narcolepsy. These lesions did not alter basic sleep-wake behavior but substantially reduced the triggering of cataplexy. Lesions also reduced the cataplexy events triggered by conditions associated with high arousal and positive emotions (i.e., wheel running and chocolate). These observations demonstrate that the amygdala is a functionally important part of the circuitry underlying cataplexy and suggest that increased amygdala activity in response to emotional stimuli could directly trigger cataplexy by inhibiting brainstem regions that suppress muscle atonia.

Amygdala lesions reduce cataplexy in orexin knock-out mice.

Narcolepsy is characterized by chronic sleepiness and cataplexy, episodes of profound muscle weakness that are often triggered by strong, positive emotions. Narcolepsy with cataplexy is caused by a loss of orexin (also known as hypocretin) signaling, but almost nothing is known about the neural mechanisms through which positive emotions trigger cataplexy. Using orexin knock-out mice as a model of narcolepsy, we found that palatable foods, especially chocolate, markedly increased cataplexy and activated neurons in the medial prefrontal cortex (mPFC). Reversible suppression of mPFC activity using an engineered chloride channel substantially reduced cataplexy induced by chocolate but did not affect spontaneous cataplexy. In addition, neurons in the mPFC innervated parts of the amygdala and lateral hypothalamus that contain neurons active during cataplexy and that innervate brainstem regions known to regulate motor tone. These observations indicate that the mPFC is a critical site through which positive emotions trigger cataplexy.

Role of the medial prefrontal cortex in cataplexy.

When living organisms become sick as a result of a bacterial infection, a suite of brain-mediated responses occur, including fever, anorexia and sleepiness. Systemic administration of lipopolysaccharide (LPS), a common constituent of bacterial cell walls, increases body temperature and non-rapid eye movement (NREM) sleep in animals and induces the production of pro-inflammatory prostaglandins (PGs). PGE2 is the principal mediator of fever, and both PGE2 and PGD2 regulate sleep-wake behavior. The extent to which PGE2 and PGD2 are involved in the effect of LPS on NREM sleep remains to be clarified. Therefore, we examined LPS-induced changes in body temperature and NREM sleep in mice with nervous system-specific knockouts (KO) for the PGE2 receptors type EP3 or EP4, in mice with total body KO of microsomal PGE synthase-1 or the PGD2 receptor type DP, and in mice treated with the cyclooxygenase (COX) inhibitor meloxicam. We observed that LPS-induced NREM sleep was slightly attenuated in mice lacking EP4 receptors in the nervous system, but was not affected in any of the other KO mice or in mice pretreated with the COX inhibitor. These results suggest that the effect of LPS on NREM sleep is partially dependent on PGs and is likely mediated mainly by other pro-inflammatory substances. In addition, our data show that the main effect of LPS on body temperature is hypothermia in the absence of nervous system EP3 receptors or in the presence of a COX inhibitor.

Yo Oishi

International Institute for Integrative Sleep Medicine (WPI-IIIS)

university of tsukuba

Polygraphic Recording Procedure for Measuring Sleep in Mice

Yo Oishi

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}International Institute for Integrative Sleep Medicine (WPI-IIIS)

university of tsukuba

Polygraphic Recording Procedure for Measuring Sleep in Mice

International Institute for Integrative Sleep Medicine (WPI-IIIS)