First-night effect reduces the beneficial effects of sleep on visual plasticity and modifies the underlying neurochemical processes.

Individuals experience difficulty falling asleep in a new environment, termed the first night effect (FNE). However, the impact of the FNE on sleep-induced brain plasticity remains unclear. Here, using a within-subject design, we found that the FNE significantly reduces visual plasticity during sleep in young adults. Sleep-onset latency (SOL), an indicator of the FNE, was significantly longer during the first sleep session than the second session, confirming the FNE. We assessed performance gains in visual perceptual learning after sleep and increases in the excitatory-to-inhibitory neurotransmitter (E/I) ratio in early visual areas during sleep using magnetic resonance spectroscopy and polysomnography. These parameters were significantly smaller in sleep with the FNE than in sleep without the FNE; however, these parameters were not correlated with SOL. These results suggest that while the neural mechanisms of the FNE and brain plasticity are independent, sleep disturbances temporarily block the neurochemical process fundamental for brain plasticity.

First-night effect reduces the beneficial effects of sleep on visual plasticity and modifies the underlying neurochemical processes.

Individuals experience difficulty falling asleep in a new environment, termed the first night effect (FNE). However, the impact of the FNE on sleep-induced brain plasticity remains unclear. Here, using a within-subject design, we found that the FNE significantly reduces visual plasticity during sleep in young adults. Sleep-onset latency (SOL), an indicator of the FNE, was significantly longer during the first sleep session than the second session, confirming the FNE. We assessed performance gains in visual perceptual learning after sleep and increases in the excitatory-to-inhibitory neurotransmitter (E/I) ratio in early visual areas during sleep using magnetic resonance spectroscopy and polysomnography. These parameters were significantly smaller in sleep with the FNE than in sleep without the FNE; however, these parameters were not correlated with SOL. These results suggest that while the neural mechanisms of the FNE and brain plasticity are independent, sleep disturbances temporarily block the neurochemical process fundamental for brain plasticity.

Towards a new understanding of pregnancy denial: the misunderstood dissociative disorder.

Pervasive pregnancy denial is a misunderstood reproductive anomaly which compromises the health of both mother and the developing fetus. Because in extreme cases, the death of the neonate at the hands of his/her mother has criminal repercussions, research has attempted to explain the origins of this clinical phenomenon. The purpose of this review is to analyze the evolution of understanding the association between pregnancy denial and neonaticide. This paper identifies the consistent similarities in symptom presentation, particularly dissociation, when a denied pregnancy ends with the death of the newborn. The common thread across the progression of the literature over time serves as a foundation for considering the development of diagnostic criteria for future inclusion in the Diagnostic and Statistical Manual of Mental Disorders. This paper reviews the seminal research from 1969 to current research up to 2020 addressing pregnancy denial and its connection to neonaticide. Peer reviewed and published articles related to key terms around "pregnancy denial," "pregnancy concealment," "neonaticide," and "dissociation" were retrieved from major databases such as PubMed, PsychINFO, JSTOR, ProQEST, ScienceDirect, and Google Scholar. Reference lists of relevant articles were also scanned to search for further papers pertaining to similarities in symptom presentation across demographic profiles. Papers were excluded if they were not available in English, or if they did not contribute to identifying consistencies in clinical presentation when a pregnancy is denied. There are clear repetitive markers that occur across studies which pertain not only to the frequent absence of certain expected indicators of pregnancy, (i.e. no morning sickness, weight gain, or sensations of fetal movement), but also the misattribution of pregnancy-related symptoms, and the consistent experience of a dissociative episode while giving birth that can unintentionally result in neonaticide. This paper concludes that dissociation is a consistently seen symptom in pervasive pregnancy denial. Dissociation, in addition to other commonly seen symptoms across cases, suggests specific diagnostic criteria that lend themselves to inclusion in the Diagnostic and Statistical Manual of Mental Disorders.

Complementary contributions of non-REM and REM sleep to visual learning.

Sleep is beneficial for learning. However, it remains unclear whether learning is facilitated by non-rapid eye movement (NREM) sleep or by REM sleep, whether it results from plasticity increases or stabilization, and whether facilitation results from learning-specific processing. Here, we trained volunteers on a visual task and measured the excitatory and inhibitory (E/I) balance in early visual areas during subsequent sleep as an index of plasticity. The E/I balance increased during NREM sleep irrespective of whether pre-sleep learning occurred, but it was associated with post-sleep performance gains relative to pre-sleep performance. In contrast, the E/I balance decreased during REM sleep but only after pre-sleep training, and the decrease was associated with stabilization of pre-sleep learning. These findings indicate that NREM sleep promotes plasticity, leading to performance gains independent of learning, while REM sleep decreases plasticity to stabilize learning in a learning-specific manner.

Reward does not facilitate visual perceptual learning until sleep occurs.

A growing body of evidence indicates that visual perceptual learning (VPL) is enhanced by reward provided during training. Another line of studies has shown that sleep following training also plays a role in facilitating VPL, an effect known as the offline performance gain of VPL. However, whether the effects of reward and sleep interact on VPL remains unclear. Here, we show that reward interacts with sleep to facilitate offline performance gains of VPL. First, we demonstrated a significantly larger offline performance gain over a 12-h interval including sleep in a reward group than that in a no-reward group. However, the offline performance gains over the 12-h interval without sleep were not significantly different with or without reward during training, indicating a crucial interaction between reward and sleep in VPL. Next, we tested whether neural activations during posttraining sleep were modulated after reward was provided during training. Reward provided during training enhanced rapid eye movement (REM) sleep time, increased oscillatory activities for reward processing in the prefrontal region during REM sleep, and inhibited neural activation in the untrained region in early visual areas in non-rapid eye movement (NREM) and REM sleep. The offline performance gains were significantly correlated with oscillatory activities of visual processing during NREM sleep and reward processing during REM sleep in the reward group but not in the no-reward group. These results suggest that reward provided during training becomes effective during sleep, with excited reward processing sending inhibitory signals to suppress noise in visual processing, resulting in larger offline performance gains over sleep.

Revision of the world species of Zambion (Hymenoptera, Ichneumonidae, Tryphoninae).

The world species of Zambion Kasparyan (Hymenoptera: Ichneumonidae: Tryphoninae) are revised including re-descriptions of Zambion monodon Kasparyan and Zambion hirtum Delobel. Five new species are described: Zambion kasparyanisp. n., Zambion rogerisp. n., Zambion eileenaesp. n., Zambion wahlisp. n. andZambion broadisp. n. A key to species is provided. The genus is endemic to Africa (Angola to Kenya) and is one of only three genera of the tribe Tryphonini recorded from the Afrotropical region.

MSI-low, a real phenomenon which varies in frequency among cancer types.

This study assessed whether low-level microsatellite instability (MSI-L) is a phenomenon specific to colorectal cancers or is also present in other tumour types. Breast (grade III ductal and lobular), endometrial and ovarian carcinomas, as well as colorectal cancers, were analysed for MSI-L using eight microsatellite markers. The markers were selected from a panel that had previously been shown to be sensitive for the detection of MSI-L in colorectal cancers. It was found that MSI-L was present in 30 of 87 (35%) colorectal cancers, 2 of 59 (3%) grade III breast carcinomas, 1 of 35 (3%) lobular breast cancers, 16 of 50 (32%) endometrial cancers, and 9 of 34 (26%) ovarian cancers. These results suggest that MSI-L is a very rare occurrence in breast carcinomas, but does occur as a real phenomenon in colorectal, endometrial, and ovarian carcinomas, which are all part of the hereditary non-polyposis colon cancer (HNPCC) syndrome. PCR artefact was also found to masquerade as MSI-L; criteria for the assessment of MSI-L are suggested to eliminate this problem.

Combination of microdissection and microarray analysis to identify gene expression changes between differentially located tumour cells in breast cancer.

Comparison of gene expression changes between cancer cells at the periphery and in the centre of breast cancers was performed using a combination of microdissection and microarray analysis. Cancer cells from the two areas were pooled separately from five patients with ductal carcinoma in situ and separately from five patients with frankly invasive cancer. Limited total RNA, 100-200 ng, from this microdissected tissue required use of the Atlas SMART trade mark Probe Amplification Kit to synthesize and amplify cDNA and make (33)P-labelled probes. Probes were then hybridized to Atlas Human Cancer 1.2 Arrays containing 1176 known genes. Triplicate analysis revealed that 22 genes changed their expression levels in the periphery relative to the central region: 15 upregulated and seven downregulated (arbitrary threshold of 1.5-fold or greater). Differences in RNA levels were confirmed by quantitative real-time PCR for two of the genes and by changes in protein levels, detected by immunohistochemistry, for a couple of representative gene products. Thus, changes in gene expression associated with variation in microanatomical location of neoplastic cells can be detected within even small developing tumour masses.