Maternal deprivation increases cell death in the infant rat brain

Prolonged separation from the mother can interfere with normal growth and development and is a significant risk factor for adult psychopathology. In rodents, separation of a pup from its mother increases the behavioral and endocrine responses to stress for the lifetime of the animal. Here we investigated whether maternal deprivation could affect brain development of infant rats via changes in the rate of cell death as measured by labeling the 3' end of DNA fragments using terminal transferase (ApopTag). At postnatal day 12 (P12), the number of cells undergoing cell death approximately doubled in the cerebral cortex, cerebellar cortex and in several white matter tracts following 24 h of maternal deprivation. Deprivation strongly increased the number of ApopTag-labeled cells at P6 but not at P20. Stroking the infant rats only partially reversed the effects of maternal deprivation. Increased cell death in white matter tracts correlated with an induction of nerve growth factor which has been previously associated with oligodendrocyte cell death. Cell birth was either unchanged or decreased in response to deprivation. These results indicate that maternal deprivation can alter normal brain development by increasing cell death of neurons and glia, and provides a potential mechanism by which early environmental stressors may influence subsequent behavior.

Thyroid cancer in pregnancy

OBJECTIVE

To compare stage at diagnosis, treatment and survival among pregnant women with thyroid cancer to non-pregnant women with thyroid cancer, and to assess the impact of treatment on maternal and perinatal outcomes.

METHODS

A database containing maternal and newborn discharge records linked to the California Cancer Registry was queried to obtain information on all thyroid cancers from 1991-1999. Women with thyroid cancer occurring during pregnancy were compared to age-matched non-pregnant women with thyroid cancer.

RESULTS

595 cases of thyroid cancers were identified (129 antepartum and 466 postpartum). About 64% of thyroid cancers were diagnosed at stage 2 among pregnant women versus 58% among non-pregnant controls. The odds of thyroid cancer were 1.5 times higher among Asian/Pacific Islanders than among Non-Hispanic White women. Pregnancy had no significant effect on mortality after diagnosis of thyroid cancer. Thyroidectomy during pregnancy was not associated with adverse maternal or neonatal outcomes.

CONCLUSIONS

Thyroid cancer discovered during or after pregnancy does not appear to have a significant impact on the prognosis of the disease.

Alpha-lipoic acid protects rat cortical neurons against cell death induced by amyloid and hydrogen peroxide through the Akt signalling pathway

Substantial evidence suggests that the accumulation of beta-amyloid (Abeta)-derived peptides contributes to the aetiology of Alzheimer's disease (AD) by stimulating formation of free radicals. Thus, the antioxidant alpha-lipoate, which is able to cross the blood-brain barrier, would seem an ideal substance in the treatment of AD. We have investigated the potential effectiveness of alpha-lipoic acid (LA) against cytotoxicity induced by Abeta peptide (31-35) (30 microM) and hydrogen peroxide (H(2)O(2)) (100 microM) with the cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) reduction and fluorescence dye propidium iodide assays in primary neurons of rat cerebral cortex. We found that treatment with LA protected cortical neurons against cytotoxicity induced by Abeta or H(2)O(2). In addition, LA-induced increase in the level of Akt in the neurons was observed by Western blot. The LA-induced neuroprotection and Akt increase were attenuated by pre-treatment with the phosphatidylinositol 3-kinase inhibitor, LY294002 (50 microM). Our data suggest that the neuroprotective effects of the antioxidant LA are partly mediated through activation of the PKB/Akt signaling pathway.

Developmental vulnerabilities to the onset and course of bipolar disorder

Different types of psychosocial stressors have long been recognized as potential precipitants of both unipolar and bipolar affective episodes and the causative agents in posttraumatic stress disorder (PTSD). New preclinical data have revealed some of the neurobiological mechanisms that could convey the long-term behavioral and biochemical consequences of early stressors. Depending on the timing, quality, quantity, and degree of repetition, maternal deprivation stress in the neonatal rodent can be associated with lifelong anxiety-like behaviors, increases in stress hormones and peptides. and proneness to drug and alcohol administration, in association with acute changes in the rate of neurogenesis and apoptosis (preprogrammed cell death) and decrements in neurotrophic factors and signal transduction enzymes necessary for learning and memory. Patients with bipolar illness who have a history of early extreme adversity (physical or sexual abuse in childhood or adolescence), compared with those without, show an earlier onset of illness, faster cycling frequencies, increased suicidality, more Axis I and Axis II comorbidities (including alcohol and substance abuse), and more time ill in more than 2 years of prospective follow-up. These findings are subject to a variety of interpretations, but to the extent that the more severe course of bipolar illness characteristics are directly and causally related to these early stressful experiences, early recognition and treatment of high-risk children could be crucial in helping to prevent or ameliorate the long-term adverse consequences of these stressors.

Kainate receptor-mediated heterosynaptic facilitation in the amygdala

Prolonged low-frequency stimulation of excitatory afferents to basolateral amygdala neurons results in enduring enhancement of excitatory synaptic responses. The induction of this form of synaptic plasticity is eliminated by selective antagonists of GluR5 kainate receptors and can be mimicked by the GluR5 agonist ATPA. Kainate receptor-mediated synaptic facilitation generalizes to include inactive afferent synapses on the target neurons, and therefore contrasts with other types of activity-dependent enduring synaptic facilitation that are input-pathway specific. Such heterosynaptic spread of synaptic facilitation could account for adaptive and pathological expansion in the set of critical internal and external stimuli that trigger amygdala-dependent behavioral responses.

Short- and Long-term Effects of Repetitive Transcranial Magnetic Stimulation on Upper Limb Motor Function after Stroke: a Systematic Review and Meta-Analysis

Objective:

The aim of this study was to evaluate the short- and long-term effects as well as other parameters of repetitive transcranial magnetic stimulation (rTMS) on upper limb motor functional recovery after stroke.

Data sources:

The databases of PubMed, Medline, Science Direct, Cochrane, and Embase were searched for randomized controlled studies reporting effects of rTMS on upper limb motor recovery published before October 30, 2016.

Review methods:

The short- and long-term mean effect sizes as well as the effect size of rTMS frequency of pulse, post-stroke onset, and theta burst stimulation patterns were summarized by calculating the standardized mean difference (SMD) and the 95% confidence interval using fixed/random effect models as appropriate.

Results:

Thirty-four studies with 904 participants were included in this systematic review. Pooled estimates show that rTMS significantly improved short-term (SMD, 0.43; P < 0.001) and long-term (SMD, 0.49; P < 0.001) manual dexterity. More pronounced effects were found for rTMS administered in the acute phase of stroke (SMD, 0.69), subcortical stroke (SMD, 0.66), 5-session rTMS treatment (SMD, 0.67) and intermittent theta burst stimulation (SMD, 0.60). Only three studies reported mild adverse events such as headache and increased anxiety .

Conclusions:

Five-session rTMS treatment could best improve stroke-induced upper limb dyskinesia acutely and in a long-lasting manner. Intermittent theta burst stimulation is more beneficial than continuous theta burst stimulation. rTMS applied in the acute phase of stroke is more effective than rTMS applied in the chronic phase. Subcortical lesion benefit more from rTMS than other lesion site.

Repetitive transcranial magnetic stimulation therapy for motor recovery in Parkinson's disease: A Meta-analysis

INTRODUCTION

Therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on motor recovery of Parkinson's disease (PD) have been reported; however, the protocols of these studies varied greatly. The aim of this meta-analysis was to evaluate the optimal rTMS parameters for motor recovery of PD.

METHODS

Electronic databases were searched for studies investigating the therapeutic effects of rTMS on motor function in patients with PD. The section III of the Unified Parkinson's Disease Rating Scale (UPDRS) was extracted as the primary outcome, and the standardized mean difference (SMD) with 95% confidence interval (CI) was calculated.

RESULTS

Twenty-three studies with a total of 646 participants were included. The pooled estimates of rTMS revealed significant short-term (SMD, 0.37; p < 0.00001) and long-term (SMD, 0.39; p = 0.005) effects on motor function improvement of PD. Subgroup analysis observed that high-frequency rTMS (HF-rTMS) was significant in improving motor function (SMD, 0.48; p < 0.00001), but low-frequency rTMS (LF-rTMS) was not. In particular, when HF-rTMS targeted over the primary motor cortex (M1), in which the bilateral M1 revealed a larger effect size than unilateral M1. Compared to single-session, multi-session of HF-rTMS over the M1 showed significant effect size. In addition, HF-rTMS over the M1 with a total of 18,000-20,000 stimulation pulses yielded more significant effects (SMD, 0.97; p = 0.01) than other dosages.

CONCLUSIONS

In conclusion, multi-session of HF-rTMS over the M1 (especially bilateral M1) with a total of 18,000-20,000 pulses appears to be the optimal parameters for motor improvement of PD.

Decreased expression of mineralocorticoid receptor mRNA in the prefrontal cortex in schizophrenia and bipolar disorder

Abnormal prefrontal cortical activity, activation of the hypothalamic-pituitary-adrenal (HPA) axis, and deficits in slow-wave sleep (SWS) have been extensively reported in patients with affective disorders and schizophrenia, yet the underlying pathophysiological mechanisms have not been completely elucidated. Mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) are two nuclear hormone receptors of primary importance in the control of stress-related and circadian HPA activity. A recent study showed that blocking brain MR activity not only enhances CRF-induced ACTH and cortisol release, but also significantly reduces SWS in humans. We hypothesized that the expression of MR would be deficient in the prefrontal cortex of patients with schizophrenia and affective disorders. The MR mRNA expression in the post-mortem prefrontal cortex of patients with major depression (MD), bipolar (BP), and schizophrenic (SZ) disorders and non-psychiatric controls (n=15 for each patient group, and n=14 for controls) was determined by in-situ hybridization. In the dorsolateral prefrontal cortex Brodmann's area 9 (BA 9), MR mRNA was significantly lower (p<0.05) in all laminae (I-VI) in BP, and in laminae I, III, IV and VI in SZ than in the controls. MR mRNA in BA 9 was negatively correlated with the duration of psychiatric illnesses. In BA 46, MR mRNA was not significantly different among groups, but was positively correlated with brain pH. These results provide the first evidence of deficient prefrontal MR mRNA expression in BP and SZ. Whether these findings may be linked to the abnormal prefrontal function, HPA axis activation, or the deficits in SWS found in these major psychiatric illnesses remains to be further explored.

Repetitive Transcranial Magnetic Stimulation as an Alternative Therapy for Cognitive Impairment in Alzheimer's Disease: A Meta-Analysis

BACKGROUND

Recent studies have indicated that repetitive transcranial magnetic stimulation (rTMS) could improve cognitive function in people with Alzheimer's disease (AD). Yet the results are inconclusive.

OBJECTIVE

This meta-analysis aimed to evaluate recent rTMS studies conducted in mild to moderate AD patients.

METHODS

PubMed, Embase, MEDLINE databases and Science Direct were searched for studies of rTMS treatment on AD patients with cognitive impairment published before February 2015. The relevant primary outcomes of cognition were extracted from those included studies. A crude standardized mean difference (SMD) with 95% confidence interval (CI) was calculated by using random effect models.

RESULTS

Seven studies with a total of 94 mild to moderate AD patients were included in this meta-analysis. A significant overall rTMS treatment effect on cognition was found for all AD patients (p = 0.0008, SMD = 1.00, 95% CI = 0.41-1.58). Stratification analysis showed that this effect is stimulation frequency- and hemisphere-dependent. High frequency stimulation (>1.0 Hz) (p <  0.05) but not low frequency stimulation (≤1.0 Hz) (p >  0.05) was significantly effective in improving the cognition of AD patients. Further, rTMS stimulation on right dorsolateral prefrontal cortex (DLPFC) and bilateral DLPFC (p <  0.05), but not on the left DLPFC (p >  0.05) was significantly effective in improving cognitive function of AD patients. A significant effect was observed in the rTMS subgroup (p <  0.05), rather than in the rTMS+drug subgroup (p >  0.05).

CONCLUSION

This meta-analysis supports that high frequency rTMS stimulation on right- or bilateral-DLPFC has significant therapeutic effect on cognitive function in patients with mild to moderate AD. Due to small number of studies included, more well-controlled rTMS studies should be evaluated in AD patients in the future.

Rat PPAR delta contains a CGG triplet repeat and is prominently expressed in the thalamic nuclei

We have isolated a new rat sequence containing motifs of a nuclear hormone receptor from a brain cDNA library. The deduced amino acid sequence encoded by the cDNA clone showed a strong homology to the human NUCI and the mouse peroxisome proliferator activated receptor delta (PPAR delta). We therefore refer to this new clone as rat PPAR delta (rPPAR delta). The new feature of rPPAR delta is a 14 CGG triplet repeat on the 5' untranslated region, not previously reported in either NUCI or mPPAR delta. We found that rPPAR delta was expressed as a 3.5-kb transcript which showed a wide distribution in adult rat tissues. Abundant expression was detected in brain, heart, skeletal muscle, kidney and lung. Weaker expression was noted in the liver, spleen and testis. To determine the specific brain localization of rPPAR delta we performed in situ hybridization analysis. Prominent expression was observed in the thalamus, particularly in the posterior part of the ventral medial nucleus, a site responsive to pain and cold stress. These results raise the possibility that PPAR delta might play a role in modulating response to thermal and pain sensations.

Decreased calcium-dependent constitutive nitric oxide synthase (cNOS) activity in prefrontal cortex in schizophrenia and depression

To further understand the potential role of nitric oxide synthase (NOS) in schizophrenia and affective disorders, we determined the calcium-dependent constitutive NOS (cNOS) enzymatic activity and protein levels in the prefrontal cortex of postmortem brains of patients with unipolar, bipolar, and schizophrenic disorders and non-psychiatric controls (n = 15 for each group). Protein levels of two NOS isoforms, nNOS and eNOS, were not significantly different from the non-psychiatric controls in any of the patient groups. However, cNOS activity was significantly lower in schizophrenic patients (mean +/- S.E. = 19.1 +/- 3.2 cpm/microg/45 min) than in the control group (28.5 +/- 3.4, P < 0.05). Trends of lower cNOS activity were found in unipolar (20.3 +/- 2.6, P = 0.062) and bipolar patients (20.8 +/- 3.0, P = 0.079). Males had significantly higher NOS activity (25.4 +/- 2, n = 36, P = 0.01) than females (17.3 +/- 1.9, n = 24), but no significant diagnosis and gender interactions were found. To minimize potential effects of extended postmortem interval (PMI) on NOS activity and proteins, the PMI was limited to 30 h and the data (n = 38) were re-analyzed. cNOS activity was significantly (P < 0.05) lower in patients with schizophrenia (15.8 +/- 5.6, P = 0.026) and unipolar depression (18.8 +/- 3.2, P = 0.042) but not in patients with bipolar illness (22.9 +/- 3.4, P = 0.21) than in the control group (29.5 +/- 3.7). cNOS activity was significantly correlated with brain pH in the total sample (r = 0.28, P < 0.05, n = 60) and in the PMI controlled subgroup (r = 0.43, P < 0.01, n = 38). Our data provide evidence of reduced cNOS activity in the postmortem brains of patients with schizophrenia and depression.

Reduction of dopamine-related transcription factors Nurr1 and NGFI-B in the prefrontal cortex in schizophrenia and bipolar disorders

Abnormal cortical and subcortical dopaminergic activities are among the most consistent neuropathological findings in schizophrenia. The molecular mechanisms remain unspecified. NGFI-B and Nurr1 are two closely related transcription factors involved in dopaminergic cell differentiation, maturation, and apoptosis. NGFI-B knockout mice show attenuated behavioral response to dopamine receptor agonists, whereas Nurr1 knockout disrupts midbrain dopaminergic neuron development. To further understand the role of Nurr1 and NGFI-B in schizophrenia and bipolar disorders, we measured Nurr1 and NGFI-B mRNA in the prefrontal cortex Brodmann's areas 9 (BA 9) and BA 46 by in situ hybridization, and the protein levels in BA 9 by Western blotting, of patients with schizophrenia, major depression, and bipolar disorders, and non-psychiatric control subjects (n=15 per group). NGFI-B mRNA (P<0.05) and protein (P<0.01) were significantly lower in patients with schizophrenia (BA 9), and NGFI-B mRNA was lower in bipolar disorder (BA 9 and BA 46) than in the controls. In the deep cortical layers of BA 46, Nurr1 mRNA was significantly (P<0.05) lower in patients with bipolar disorder and schizophrenia than in the controls. Nurr1 protein in BA 9 was significantly lower in major depression (P<0.05) and lower at a trend level in schizophrenia (P=0.056) than in the controls. These data show a deficient prefrontal NGFI-B and Nurr1 expression in schizophrenia and bipolar disorder. Further study may elucidate if and how these deficiencies could be associated with abnormal dopaminergic functions seen in both illnesses.

Stimulation of the mitogen-activated protein kinase cascade and tyrosine phosphorylation of the epidermal growth factor receptor by hepatopoietin

Hepatopoietin (HPO) is a novel human hepatotrophic growth factor, which specifically stimulates proliferation of cultured primary hepatocytes in vitro and liver regeneration after liver partial hepatectomy in vivo. Recently, the identification of the mitogenic effect of HPO on hepatoma cell lines and the existence of HPO-specific receptors indicate that HPO acts via its specific cell surface receptor. However, the molecular mechanism of HPO action is not fully elucidated. In this report, we examined the signal transduction events induced by HPO in hepatoma cell line (HepG2). Our results demonstrated that HPO induces phosphorylation of mitogen-activated protein kinase kinase and mitogen-activated protein kinase (MAPK) in a rapid and transient manner. HPO stimulates tyrosine phosphorylation of epidermal growth factor receptor (EGFR). Furthermore, we observed that both MAPK activation and the mitogenic effect of HPO on HepG2 cells were completely blocked by AG1478, a specific inhibitor of EGFR tyrosine kinase activity. However, the effects of HPO were not antagonized by an EGFR-blocking antibody, mAb528, which blocks the interaction between epidermal growth factor and EGFR, indicating that stimulation of tyrosine phosphorylation of EGFR by HPO was not mediated by epidermal growth factor. In contrast, genistein, a general tyrosine kinase inhibitor, significantly attenuated the tyrosine phosphorylation of EGFR in response to HPO. In conclusion, our results suggest that tyrosine phosphorylation of EGFR may play a critical role in MAPK activation and mitogenic stimulation by HPO.

Designing metal-peptide models for protein structure and function

Recent progress in the rational design of metal sites within peptide model systems shows increasing control in the placement of metals within helical bundles and inclusion of sophisticated elements such as second-sphere ligand interactions. A crystallographically characterized two-metal peptide model for diiron proteins represents a major achievement in de novo design methodologies. Increasingly complex and robust models for electron transfer through and between helices, and electrode-supported electron-transfer peptides, have been constructed. Design elements for peptide-supported ferredoxins and mononuclear Fe(II) and Zn(II) sites have been refined.

Effects of High-Frequency Transcranial Magnetic Stimulation for Cognitive Deficit in Schizophrenia: A Meta-Analysis

Objective: Repetitive transcranial magnetic stimulation (rTMS) has been applied to dorsolateral prefrontal cortex (DLPFC) to improve cognitive function of patients with schizophrenia (SZs). The aim of this meta-analysis was to evaluate whether a high-frequency rTMS course could enhance cognitive function in SZs. Methods: Studies published in PubMed, Cochrane Library, Embase, ScienceDirect, and Web of science were searched until April 2018. The search terms included: "repetitive transcranial magnetic stimulation" or "Rtms," "SZ," or "schizophrenia," and "neuro-cognition" or "neurocognitive performance" or "cognitive effects" or "cognitive" or "cognition" or "working memory" or "executive function" or "language function" or "processing speed," After screening the literatures according to inclusion and exclusion criteria, extracting data, and evaluating the methodological quality of the included studies, a meta-analysis was performed using RevMan 5.3 software (The Cochrane Collaboration, USA). Results: A total of 9 studies on cognitive dysfunction of SZs were included and involved 351 patients. A significant efficacy of high-frequency rTMS on working memory in SZs was found compared to sham stimulation [p = 0.009, standardized mean difference (SMD) = 0.34]. Specifically, rTMS treatment positioned on the left DLPFC, with a total pluses <30,000 was more significantly more effective in improving the working memory (SMD = 0.33, p = 0.03). No improvement was found in other cognitive domains such as executive function, attention, processing speed, and language function. For the follow-up observations, high-frequency rTMS had long-lasting sustained effects on working memory (SMD = 0.45, p = 0.01) and language function (SMD = 0.77, p = 0.02) in SZs. Conclusions: High-frequency rTMS over the left DLPFC with a total pulses <30,000 stimulation could significantly improve working memory in SZs for an extended period of time.

Identification and characterization of receptor for mammalian hepatopoietin that is homologous to yeast ERV1

Hepatopoietin (HPO) is a novel polypeptide mitogen specific for hepatocytes and hepatoma cell lines, which is derived from liver and supports its regeneration. To determine whether HPO acts via a receptor-based signal transduction, recombinant human hepatopoietin was labeled by iodination and used to characterize its binding activity by specific displacement test and Scatchard analysis in primarily cultured rat hepatocytes and human hepatoma Hep-G2 cells. The binding was saturable and specific because it was replaceable by HPO but not by epidermal growth factor, transforming growth factor-alpha, or insulin. Scatchard analysis indicated the presence of a single class of high affinity receptor with dissociation constant (Kd) of 2 and 0.7 pM, and a receptor density of about 10, 000 sites/cell and 55,000 sites/cell in the rat hepatocytes and human hepatoma cells, respectively. The Kd values were consistent with the half-maximum dose of HPO activity. Affinity cross-linking of the receptor with 125I-HPO revealed a polypeptide of molecular mass approximately 90 kDa by SDS-polyacrylamide gel electrophoresis. Thus, the molecular mass of the HPO receptor was calculated to be about 75 kDa. These data demonstrated the existence of an HPO receptor in hepatocytes and hepatoma cells, which may account for biological effect.

Expression pattern of the cannabinoid receptor genes in the frontal cortex of mood disorder patients and mice selectively bred for high and low fear

Although the endocannabinoid system (ECS) has been implicated in brain development and various psychiatric disorders, precise mechanisms of the ECS on mood and anxiety disorders remain unclear. Here, we have investigated developmental and disease-related expression pattern of the cannabinoid receptor 1 (CB1) and the cannabinoid receptor 2 (CB2) genes in the dorsolateral prefrontal cortex (PFC) of humans. Using mice selectively bred for high and low fear, we further investigated potential association between fear memory and the cannabinoid receptor expression in the brain. The CB1, not the CB2, mRNA levels in the PFC gradually decrease during postnatal development ranging in age from birth to 50 years (r2 > 0.6 & adj. p < 0.05). The CB1 levels in the PFC of major depression patients were higher when compared to the age-matched controls (adj. p < 0.05). In mice, the CB1, not the CB2, levels in the PFC were positively correlated with freezing behavior in classical fear conditioning (p < 0.05). These results suggest that the CB1 in the PFC may play a significant role in regulating mood and anxiety symptoms. Our study demonstrates the advantage of utilizing data from postmortem brain tissue and a mouse model of fear to enhance our understanding of the role of the cannabinoid receptors in mood and anxiety disorders.

Metabolic acetate therapy for the treatment of traumatic brain injury

Patients suffering from traumatic brain injury (TBI) have decreased markers of energy metabolism, including N-acetylaspartate (NAA) and ATP. In the nervous system, NAA-derived acetate provides acetyl-CoA required for myelin lipid synthesis. Acetate can also be oxidized in mitochondria for the derivation of metabolic energy. In the current study, using the controlled cortical impact model of TBI in rats, we investigated the effects of the hydrophobic acetate precursor, glyceryltriacetate (GTA), as a method of delivering metabolizable acetate to the injured brain. We found that GTA administration significantly increased the levels of both NAA and ATP in the injured hemisphere 4 and 6 days after injury, and also resulted in significantly improved motor performance in rats 3 days after injury.

Adaptation and mal-adaptation to ambient hypoxia; Andean, Ethiopian and Himalayan patterns

The study of the biology of evolution has been confined to laboratories and model organisms. However, controlled laboratory conditions are unlikely to model variations in environments that influence selection in wild populations. Thus, the study of “fitness” for survival and the genetics that influence this are best carried out in the field and in matching environments.

Therefore, we studied highland populations in their native environments, to learn how they cope with ambient hypoxia. The Andeans, African highlanders and Himalayans have adapted differently to their hostile environment.

Chronic mountain sickness (CMS), a loss of adaptation to altitude, is common in the Andes, occasionally found in the Himalayas; and absent from the East African altitude plateau.

We compared molecular signatures (distinct patterns of gene expression) of hypoxia-related genes, in white blood cells (WBC) from Andeans with (n = 10), without CMS (n = 10) and sea-level controls from Lima (n = 20) with those obtained from CMS (n = 8) and controls (n = 5) Ladakhi subjects from the Tibetan altitude plateau. We further analyzed the expression of a subset of these genes in Ethiopian highlanders (n = 8). In all subjects, we performed the studies at their native altitude and after they were rendered normoxic.

We identified a gene that predicted CMS in Andeans and Himalayans (PDP2). After achieving normoxia, WBC gene expression still distinguished Andean and Himalayan CMS subjects.

Remarkably, analysis of the small subset of genes (n = 8) studied in all 3 highland populations showed normoxia induced gene expression changes in Andeans, but not in Ethiopians nor Himalayan controls. This is consistent with physiologic studies in which Ethiopians and Himalayans show a lack of responsiveness to hypoxia of the cerebral circulation and of the hypoxic ventilatory drive, and with the absence of CMS on the East African altitude plateau.

Subjective Cognitive Decline and Related Cognitive Deficits

Since late stage dementia, including Alzheimer's disease (AD), cannot be reversed by any available drugs, there is increasing research interest in the preclinical stage of AD, i.e., subjective cognitive decline (SCD). SCD is characterized by self-perceptive cognitive decline but is difficult to detect using objective tests. At SCD stage, the cognitive deficits can be more easily reversed compared to that of mild cognitive impairment (MCI) and AD only if accurate diagnosis of SCD and early intervention can be developed. In this paper, we review the recent progress of SCD research including current assessment tools, biomarkers, neuroimaging, intervention and expected prognosis, and the potential relevance to traumatic brain injury (TBI)-induced cognitive deficits.

Decreased prefrontal CaMKII alpha mRNA in bipolar illness

Ca2+/calmodulin-dependent protein kinase II (CaMKII) plays critical roles in neurotransmission, synaptic plasticity, learning and memory. The aim of this study was to examine, by in situ hybridization, prefrontal cortical expression of CaMKII alpha mRNA in postmortem brains of unipolar, bipolar, schizophrenic, and control subjects. Compared to controls, bipolar patients had significantly lower levels of CaMKII alpha mRNA in laminae I-VI of Brodmann's area 9 and laminae I-III and VI of area 46. Unipolar patients also exhibited significantly lower levels of CaMKII alpha mRNA in laminae I-IV of area 9 than did controls. The significant decrease in CaMKII alpha mRNA in bipolar patients could be associated with some of the affective and cognitive alterations that have been linked to prefrontal cortical dysfunction in bipolar disorder, although this requires further direct examination.

Repetitive transcranial magnetic stimulation as an alternative therapy for dysphagia after stroke: a systematic review and meta-analysis

OBJECTIVES

A meta-analysis and systematic review was conducted to investigate the potential effects of repetitive transcranial magnetic stimulation on dysphagia in patients with stroke, including different parameters of frequency and stimulation site.

METHODS

PubMed, Embase, MEDLINE databases and the Cochrane Library, were searched for randomized controlled studies of repetitive transcranial magnetic stimulation treatment of dysphagia published before March 2016.

RESULTS

Six clinical randomized controlled studies of a total of 163 stroke patients were included in this meta-analysis. A significant effect size of 1.24 was found for dysphagic outcome (mean effect size, 1.24; 95% confidence interval (CI), 0.67-1.81). A subgroup analysis based on frequency showed that the clinical scores were significantly improved in dysphagic patients with low frequency repetitive transcranial magnetic stimulation treatment ( P < 0.05) as well as high frequency repetitive transcranial magnetic stimulation treatment ( P < 0.05). A stimulation site stratified subgroup analysis implied significant changes in stroke patients with dysphagia for the unaffected hemisphere ( P < 0.05) and the bilateral hemisphere stimulation ( P < 0.05), but not for the affected hemisphere ( P > 0.05). The analysis of the follow-up data shows that patients in the repetitive transcranial magnetic stimulation groups still maintained the therapeutic benefit of repetitive transcranial magnetic stimulation four weeks after the last session of repetitive transcranial magnetic stimulation therapy ( P < 0.05).

CONCLUSION

This meta-analysis indicates that repetitive transcranial magnetic stimulation has a positive effect on dysphagia after stroke. Compared with low-frequency repetitive transcranial magnetic stimulation, high-frequency repetitive transcranial magnetic stimulation may be more beneficial to the patients. This meta-analysis also supports that repetitive transcranial magnetic stimulation on an unaffected - or bilateral - hemisphere has a significant therapeutic effect on dysphagia.

Neural plasticity and emotional memory

Posttraumatic stress disorder is the pathological replay of emotional memory formed in response to painful, life-threatening, or horrifying events. In contrast, depression is often precipitated by more social context-related stressors. New data suggest that different types of life experiences can differentially impact biochemistry, physiology, anatomy, and behavior at the level of changes in gene expression. Repeated separation of neonatal rat pups from their mother results in many long-lasting alterations in biology and behavior paralleling that in depression, including hypercortisolism. The role of the amygdala in modulating emotional memory is highlighted, as well as some of its unique properties such as metaplasticity (i.e., the differential direction of long-term adaptation, either potentiation or depression) in response to the same input as a function of the prior history of stimulation. The implications of these emerging data on the physiological and molecular mechanisms underlying emotional memory emphasize the particular importance of prevention and early intervention.

Increased sensitivity to seizures in repeated exposures to hyperbaric oxygen: role of NOS activation

Nitric oxide is involved in the mechanism of hyperbaric oxygen (HBO(2)) brain toxicity as nitric oxide synthase (NOS) inhibitors delay latent time before the onset of seizures. The purpose of this study was to investigate if seizures affect sensitivity to convulsions during subsequent exposure to HBO(2) and to determine if NOS activity and expression is changed after HBO(2) seizures. Rats were exposed to 5 atm (gauge pressure) 100% O(2) until seizures recorded by electroencephalograph (EEG) and reexposed 1, 2, or 6 days later. Latency to seizures was significantly shorter (P<0.05) in animals reexposed 1 or 2 days after the first exposure. Activity of calcium-dependent NOS activity in cortex was significantly higher 1 and 2 days after seizures compared with controls (P<0.05), while calcium-independent NOS activity was not changed during the 6-day post-seizure interval. The expression of neuronal NOS (nNOS) protein determined by Western blot was higher 1 and 2 days after seizures (P<0.05), while the expression of endothelial (eNOS) and inducible (iNOS) remained unchanged. nNOS upregulation 1 and 2 days after seizures and protection against HBO(2) seizures by nNOS-specific inhibitor 7-nitroindazole (7-NI) suggest possible involvement of NO in the mechanism of increased sensitivity to HBO(2) in reexposures.

Impact of repeated stress on traumatic brain injury-induced mitochondrial electron transport chain expression and behavioral responses in rats

A significant proportion of the military personnel returning from Iraq and Afghanistan conflicts have suffered from both mild traumatic brain injury (mTBI) and post-traumatic stress disorder. The mechanisms are unknown. We used a rat model of repeated stress and mTBI to examine brain activity and behavioral function. Adult male Sprague-Dawley rats were divided into four groups: Naïve; 3 days repeated tail-shock stress; lateral fluid percussion mTBI; and repeated stress followed by mTBI (S-mTBI). Open field activity, sensorimotor responses, and acoustic startle responses (ASRs) were measured at various time points after mTBI. The protein expression of mitochondrial electron transport chain (ETC) complex subunits (CI-V) and pyruvate dehydrogenase (PDHE1α1) were determined in four brain regions at day 7-post mTBI. Compared to Naïves, repeated stress decreased horizontal activity; repeated stress and mTBI both decreased vertical activity; and the mTBI and S-mTBI groups were impaired in sensorimotor and ASRs. Repeated stress significantly increased CI, CII, and CIII protein levels in the prefrontal cortex (PFC), but decreased PDHE1α1 protein in the PFC and cerebellum, and decreased CIV protein in the hippocampus. The mTBI treatment decreased CV protein levels in the ipsilateral hippocampus. The S-mTBI treatment resulted in increased CII, CIII, CIV, and CV protein levels in the PFC, increased CI level in the cerebellum, and increased CIII and CV levels in the cerebral cortex, but decreased CI, CII, CIV, and PDHE1α1 protein levels in the hippocampus. Thus, repeated stress or mTBI alone differentially altered ETC expression in heterogeneous brain regions. Repeated stress followed by mTBI had synergistic effects on brain ETC expression, and resulted in more severe behavioral deficits. These results suggest that repeated stress could have contributed to the high incidence of long-term neurologic and neuropsychiatric morbidity in military personnel with or without mTBI.