The Activation of NMDA Receptor–ERK Pathway in the Central Amygdala is Required for the Expression of Morphine-Conditioned Place Preference in the Rat

Reinforcing effects of addictive drugs can be evaluated with the conditioned place preference (CPP) test which involves both the action of drugs and environmental cues. However, the encoded neural circuits and underlying signaling mechanism are not fully understood. In this study, we have used morphine-CPP model in the rat and characterized the role of N-methyl-d-aspartate (NMDA) receptor and the phosphorylation of extracellular signal-regulated kinase (ERK) in the central nuclei of amygdala (CeA) in the expression of morphine-induced CPP. We have found that morphine repeated pairing treatment causes a significant preference for compartment paired with morphine after 1 day or 7 days post-training, which is associated with increased ERK1/2 phosphorylation (p-ERK1/2, a measure of ERK activity) in the CeA. More than 80% of the positive p-ERK1/2 neurons express NMDA receptor subunit NR1 by double immunofluorescence studies. The infusion of either MEK inhibitor U0126 or NMDA receptor antagonist MK-801 in the CeA not only suppresses the activation of ERK1/2 in the CeA but also abolishes the expression of CPP. These results suggest that the activation of the NMDA receptor–ERK signaling pathway in the CeA is required for the expression of morphine-induced place preference in the rat.     

Changes in the Expression of Genes of the Glutamate Transporter and Subunits of the NMDA and AMPA Receptors in the Rat Amygdala in the Lithium–Pilocarpine Model of Epilepsy

The molecular changes in the glutamatergic system of the rat amygdala were studied during the latent phase of the lithium–pilocarpine model of temporal lobe epilepsy in order to identify the potential involvement of these changes in epileptogenesis. The real-time PCR method was used to evaluate the mRNA expression of the NMDA and AMPA receptor subunits, as well as the excitatory amino acid transporter-2 (EAAT2) in the basolateral nucleus of the amygdala 7 days after the seizures caused by administration of pilocarpine. The results of the experiments were as follows: (1) an increase in the expression ratio of the GluN2a/GluN2b NMDA receptor subunits with an unchanged expression level of the GluN1 subunit; (2) increased expression of the GluA2 subunit of AMPA receptors with the invariance of GluA1, and (3) enhanced expression of the EAAT2. According to literature data, the expression of the same genes decreased in the hippocampus in the same model of epilepsy. Neurodegeneration was reported in both brain regions. The opposite changes in the expression of the glutamatergic system genes in the hippocampus and amygdala during the latent period of the lithium–pilocarpine model suggest the occurrence of factors that can both contribute to and hinder epileptogenesis.     

Attenuation of Aluminum Chloride-Induced Neuroinflammation and Caspase Activation Through the AKT/GSK-3β Pathway by Hesperidin in Wistar Rats

Hesperidin, a flavanoglycone abundantly present in citrus fruits, is reported to have antioxidant, anti-inflammatory, and neuroprotective properties. Previous reports from our laboratory indicated the neuroprotective effect of hesperidin against aluminum chloride (AlCl₃)-induced memory loss, acetylcholine esterase hyperactivity, oxidative stress, and enhanced expression of amyloid β protein biosynthesis-related markers. However, their role on AlCl₃-induced inflammation, caspase activation, Tau pathology, altered Akt/GSK 3β signaling pathway, and Aβ clearance marker has not yet been fully elucidated. Intraperitonial injection of AlCl₃ (100 mg/kg body weight) for 60 days significantly elevated the expressions of insulin-degrading enzyme (IDE), cyclin-dependent kinase 5 (CDK 5), and phosphoTau (pTau); inflammatory markers such as glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), NF-kB, cyclooxygenase-2 (COX-2), interleukin (IL)-1β, IL-4, IL-6, tumor necrosis factor-alpha (TNF-α), inducible nitric oxide synthase (iNOS); and apoptotic markers including cytosolic cytochrome c (cyto c), caspase-3, caspase-8, and caspase-9, and lowered expressions of mitochondrial cyto c, phospho-Akt (pAkt) and phospho-glycogen synthase kinase-3β (pGSK-3β) in the hippocampus and cortex. Co-administration of hesperidin to AlCl₃ rats for 60 days significantly ameliorated the aluminum-induced pathological changes. The behavioral studies also supported the above findings. Our results imply that treatment with hesperidin might be a potent option for treating the symptoms of cognitive impairment in Alzheimer’s disease by targeting its most prominent hallmarks.     

Caspase-3 is Involved in Aluminum-Induced Impairment of Long-Term Potentiation in Rats Through the Akt/GSK-3β Pathway

A number of studies have indicated that aluminum (Al) exposure can impair learning and memory function. The ability of Al to inhibit hippocampal long-term potentiation (LTP) suggests the possibility of Al impairing synaptic plasticity. LTP is dependent on the externalization of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors (AMPAR). The protein kinase B (Akt) and glycogen synthase kinase-3β (GSK-3β) signaling pathway has been demonstrated to mediate AMPAR delivery. A mechanism by which caspase-3 cleaves Akt is involved in synaptic plasticity, but the underlying molecular mechanism involved has still not been elucidated. The purpose of this study was to investigate the mechanism of LTP impairment and the related signaling pathway disturbance induced by Al exposure. Our results reveal that Al treatment produces a dose-dependent suppression of LTP and decreases in the AMPAR subunits GluR1 and GluR2, in both membrane and total cell extracts. Al caused increased accumulation of active caspase-3 and a gradual decrease in Akt and pGSK-3β. Interestingly, Al depressed LTP and AMPAR protein concentration. N-benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-fluoromethyl ketone (a caspase-3 inhibitor) reversed the Al-induced LTP inhibition, increased levels of active caspase-3, and decreased AMPAR levels in both total and membrane-enriched extracts. It also decreased Akt and pGSK-3β. The molecular mechanism of Al-induced LTP impairment might be related to the activation of caspase-3, cleavage of Akt, activation of GSK-3β, and inhibition of the externalization of AMPAR.     

Quanti?cation of Tyrosine Hydroxylase and Erb B4 in the Locus Coeruleus of Mood Disorder Patients Using a Multispectral Method to Prevent Interference with Immunocytochemical Signals by Neuromelanin

The locus coeruleus(LC) has been studied in major depressive disorder(MDD) and bipolar disorder(BD). A major problem of immunocytochemical studies in the human LC is interference with the staining of the immunocytochemical end-product by the omnipresent natural brown pigment neuromelanin. Here, we used a multispectral method to untangle the two colors: blue immunocytochemical staining and brown neuromelanin.We found significantly increased tyrosine hydroxylase(TH) in the LC of MDD patients—thus validating the method—but not in BD patients, and we did not find significant changes in the receptor tyrosine-protein kinase ErbB4 in the LC in MDD or BD patients. We observed clear co-localization of ErbB4, TH, and neuromelanin in the LC neurons. The different stress-related molecular changes in the LC may contribute to the different clinical symptoms in MDD and BD.     

A Multitrait–Multimethod Analysis of the Construct Validity of Child Anxiety Disorders in a Clinical Sample

The present study examines the construct validity of separation anxiety disorder (SAD), social phobia (SoP), panic disorder (PD), and generalized anxiety disorder (GAD) in a clinical sample of children. Participants were 174 children, 6 to 17 years old (94 boys) who had undergone a diagnostic evaluation at a university hospital based clinic. Parent and child ratings of symptom severity were assessed using the Multidimensional Anxiety Scale for Children (MASC). Diagnostician ratings were obtained from the Anxiety Disorders Interview Schedule for Children and Parents (ADIS: C/P). Discriminant and convergent validity were assessed using confirmatory factor analytic techniques to test a multitrait–multimethod model. Confirmatory factor analyses supported the current classification of these child anxiety disorders. The disorders demonstrated statistical independence from each other (discriminant validity of traits), the model fit better when the anxiety syndromes were specified than when no specific syndromes were specified (convergent validity), and the methods of assessment yielded distinguishable, unique types of information about child anxiety (discriminant validity of methods). Using a multi-informant approach, these findings support the distinctions between childhood anxiety disorders as delineated in the current classification system, suggesting that disagreement between informants in psychometric studies of child anxiety measures is not due to poor construct validity of these anxiety syndromes.     

Learning face–name associations in early-stage dementia: Comparing the effects of errorless learning and effortful processing

Some recent studies suggest that errorless learning principles may be beneficial in memory rehabilitation for people with dementia, while others indicate that effortful processing may be more important. The present study compared the effects of four different learning techniques, varying in level of effort required and number of errors elicited, on free recall, cued recall and recognition of novel and previously known associations among people with early-stage dementia. Ten participants with a diagnosis of early-stage Alzheimer's, vascular or mixed dementia learned novel and previously familiar face–name associations with each of four techniques – vanishing cues, forward cues, target selection, and paired associate learning – in a within-subjects design. All conditions produced significant learning for both novel and familiar associations. There were no significant differences between conditions, although mean scores were slightly higher for errorful conditions. Reducing errors did not produce any benefits. Enhancing level of effort had no significant effects for familiar associations, but high-effort conditions were significantly more effective than low-effort conditions in facilitating cued recall of novel associations. The results confirm that memory rehabilitation techniques can produce significant benefits, but do not support the view that error reduction during learning facilitates greater improvement in early-stage dementia. Effort enhancement may be more important, especially when learning novel associations.     

Distribution of Androgen and Oestrogen Receptors-α in the Seminal Vesicle-Related Spinal Neurones in Male Rats

The seminal vesicles are male accessory sex glands that contribute much of the seminal fluid volume. Previous studies have suggested that the majority of autonomic innervations to the rat seminal vesicles originate from the bilateral major pelvic ganglia. Many preganglionic autonomic neurones innervating the pelvic ganglion were expressed androgen receptors (AR) or oestrogen receptor (ER)-α immunoreactivity. However, direct neuroanatomic data regarding the distribution of AR and ER-α in seminal vesicle related-spinal neurones are lacking. In the present study, a nonvirulent pseudorabies virus (PRV-152 strain) was used in a retrograde tracing experiment. Four days after PRV injection into the seminal vesicles of male rats, spinal cord sections were prepared. Double- and triple-fluorescence techniques using AR and ER-α with choline acetyltransferase (ChAT) and PRV were used to investigate the AR and ER-α distribution in the seminal vesicles related spinal neurones in male rats. In lamina X, 14% of the PRV-labelled neurones in the L1–L4 segments and 43% in the L5–S1 segments were double-labelled with AR. In the L1–L4 segments, 6% of PRV-labelled neurones and 26% in the L5–S1 segments were double-labelled with ER-α. In the intermedial cell column area, 10% of PRV-labelled neurones in the L1–L4 segments and 47% of PRV-labelled neurones in the L5–S1 segments were double-labelled with AR. Up to 16% of PRV-labelled neurones in the L5–S1 segments were double-labelled with ER-α. No PRV-labelled neurones in the L1–L4 segments were double-labelled with ER-α. However, for the AR and ER-α/PRV/ChAT triple-fluorescence experiments, very few seminal vesicle preganglionic neurones expressed AR or ER-α. Our data suggests that many spinal interneurones but not preganglionic neurones involved in the seminal vesicle control in male rats were double-labelled with AR or ER-α, and they were mainly located at the parasympathetic level in the spinal cord.     

[Gly14]-Humanin Protects Against Amyloid β Peptide-Induced Impairment of Spatial Learning and Memory in Rats

Alzheimer disease（AD）, a progressive neurodegenerative disorder, is characterized by cognitive decline and the accumulation of senile plaques in the brain.Amyloid b protein（Aβ） in the plaques is thought to be responsible for the memory loss in AD patients. [Gly14]-humanin（HNG）, a derivative of humanin（HN）, has much stronger neuroprotective effects than natural HN in vitro.However, clarification of the Aβ active center and the neuroprotective mechanism of HN still need in vivo evidence. The present study first compared the in vivo biological effects of three Aβ fragments（1–42, 31–35, and 35–31） on spatial memory in rats, and investigated the neuroprotective effects and molecular mechanisms of HNG. The results showed that intrahippocampal injection of Aβ_1–42and Aβ_31–35almost equally impaired spatial learning and memory, but the reversed sequence Aβ_35–31 did not have any effect; a high dose of Aβ_31–35（20 nmol） produced a more detrimental response than a low dose（2 nmol）; Aβ_31–35 injection also disrupted gene and protein expression in the hippocampus, with up-regulation of caspase3 and down-regulation of STAT3; pretreatment with HNG not only protected spatial memory but also rescued STAT3 from Aβ-induced disruption; and the neuroprotective effects of HNG were effectively counteracted by genistein, a specific tyrosine kinase inhibitor. These results clearly show that sequence 31–35 in Aβ is the shortest active center responsible for the neurotoxicity of Aβ from molecule to behavior; and HNG protects spatial learning and memory in rats against Aβ-induced insults; and probably involves the activation of tyrosine kinases and subsequent beneficial modulation of STAT3 and caspase3.     

The Importance of Mindfulness in Explaining the Relationship Between Adolescents’ Anxiety and Dropout Intentions

Failure to complete high school is associated with a myriad of negative outcomes. Some research has suggested a link between student anxiety and risk of dropout. Recently, there has been increasing evidence that mindfulness may diminish anxiety in adolescents; however, the relationship between anxiety, mindfulness and dropout has yet to be investigated. Thus, the current study examined the role of mindfulness and anxiety in adolescents’ intentions for dropping out of school. The sample consisted of 471 Grade 9 students (53.1 % female; M _age = 14.45 years, SD = .527). All participants completed the Beck Anxiety Inventory for Youth, the Child and Adolescent Mindfulness Measure and an English translation of Le questionnaire de dépistage des élèves à risque de décrochage scolaire (questionnaire for screening of students at risk of school dropout) in groups. Results showed that anxiety demonstrated a moderate significant negative association with mindfulness, and a low significant positive association with reports of dropout intention. A significant low negative correlation was also found for mindfulness and dropout intention. Interestingly, mindfulness was found to partially mediate the relationship between anxiety and dropout intention, with a medium effect. Implications for future research and practice regarding mindfulness as a protective factor for dropout intention are discussed.     

Involvement of postsynaptic α1- and α2-adrenoceptors in the flexor reflex activity in the spinal Rats

Summary Clonidine (0.2 mg/kg i.v.) and St 587 (1 mg/kg i.v.), selective agonsists of ₂- and ₁-adrenoceptors, respectively, increased the flexor reflex amplitude in the spinal rat. Yohimbine and rauwolscine, ₂-adrenoceptor antagonists, inhibited dose-dependently the effect of clonidine but not of St 587. However, prazosin and clozapine, ₁-adrenoceptor antagonists, diminished the action of both agonists in a dose-dependent manner. After central chemosympathectomy caused by 6-OH-DA or DSP-4 the response to clonidine did not differ from that in the sham-operated animals. In 6-OH-DA treated rats yohimbine (1 mg/kg i.v.) antagonized the effect of clonidine to the same extent as it did in unlesioned animals. It is concluded that the results are functional evidence that ₁- and ₂-adrenoceptors are present in the rat spinal cord, and stimulation of each receptor increases flexor reflex activity.     

The Effect of Cyclosporine and the Consequences in Hepatic and Renal Function Following Ischemic Stroke in a Rats’ Model

IntroductionRecent studies have indicated that the damaging effects of stroke are not only limited to the brain. We sought to examine the changes of liver and renal enzymes in the acute phase of ischemic stroke and to investigate possible explanations and therapeutic options, concerning in particular the functional alterations of peripheral organs after administration of an anti-inflammatory agent.Material/MethodsTwelve-week-old Wistar male rats were randomly divided into control and Cyclosporine groups (n = 10 each). Cyclosporine was given orally by gavage for 5 days prior to cerebral ischemia at a total volume of 15 mg/kg/day. All animals were subjected to 60 minutes focal ischemia by filament occlusion of the middle cerebral artery. Serum concentrations of Creatinine, Urea, SGOT, SGPT, and γGT were determined at the time before surgery and after 60 minutes brain ischemia.ResultsComparing data of 2 time-points, in both groups the serum liver enzyme levels increased progressively during the ischemic period. The liver enzymes and Urea were significantly lower in the Cyclosporine group than in the control group and the levels of Creatinine were slightly higher in the Cyclosporine group, in both time-points.ConclusionsThe detection of high liver enzyme serum levels in the acute phase of ischemic stroke implies the secondary effect of cerebral infraction on the peripheral organs and particularly on the liver function. Cyclosporine seems to exhibit a protective activity and to affect both liver and renal function after ischemic stroke.     

How Does Maternal Separation Affect the Cerebellum? Assessment of the Oxidative Metabolic Activity and Expression of the c-Fos Protein in Male and Female Rats

Early life stress increases the risk of abnormal brain development, and it is associated with psychological disorders. Maternal separation is an established animal model of early life stress that produces changes in the development of the central nervous system. The objective of this study was to evaluate the effect of maternal separation on the rat cerebellum, both behaviourally and physiologically. We used 32 rats, males (n = 8) and females (n = 7), subjected to maternal separation for 21 days and a control group (9 males and 8 females). Spatial reference memory was assessed using the Morris water maze, and brain metabolic activity and the expression of an immediate early gene were determined, respectively, using the histochemical technique of cytochrome c oxidase and the immunocytochemistry of c-Fos. Results showed that both groups successfully performed the spatial memory task. Although there were no behavioural differences, the experimental group showed lower metabolic activity in the medial nucleus of the cerebellum, as well as fewer c-Fos-positive cells in the three deep nuclei of the cerebellum. These decreases could contribute to the emotional or behavioural impairments reported in maternal separation subjects.     

Selective Mutism and Social Anxiety Disorder: All in the Family?

OBJECTIVE: To examine the history of lifetime psychiatric disorders in the parents of children with selective mutism (SM) compared to parents of children in a control group. METHOD: Seventy parent dyads (n = 140) of children with lifetime SM and 31 parent dyads (n = 62) of children without SM were interviewed with the Structured Clinical Interview for DSM-IV (IV and II) anxiety disorders, mood disorders, avoidant personality disorder, and schizoid personality disorder modules via telephone. Interviewers were blind to proband status. The NEO Personality Inventory was also administered. RESULTS: Lifetime generalized social phobia was present in 37.0% of SM parents compared to 14.1% of control parents (chi2 = 10.98; p < .001; odds ratio 3.6, 95% confidence interval 1.6-7.9). Avoidant personality disorder was present in 17.5% of the SM parents compared to 4.7% of control parents (chi2 = 6.18; p < .05; odds ratio 4.3, 95% confidence interval 1.3-14.9). The proportion of parents with other psychiatric disorders was not different between groups. SM parents had higher neuroticism and lower openness scores on the NEO Personality Inventory than control parents. CONCLUSIONS: These results support earlier uncontrolled findings of a familial relationship between generalized social phobia and SM.     

Enhanced delivery and bioactivity of the neurturin neurotrophic factor through focused ultrasound—mediated blood–brain barrier opening in vivo

The blood–brain barrier (BBB) constitutes a major obstacle in brain drug delivery. Focused ultrasound (FUS) in conjunction with microbubbles has been shown to open the BBB noninvasively, locally, and transiently to allow large molecules diffusion. Neurturin (NTN), a member of the glial-derived neurotrophic factor (GDNF) family, has been demonstrated to have neuroprotective and regenerative effects on dopaminergic neurons in vivo using invasive drug delivery methods. The brain''s ascending nigrostriatal pathway is severely damaged in Parkinson''s disease (PD), and therefore the substantia nigra (SN) and striatal caudoputamen (CP) were selected as the target areas. The objective of the study was to investigate whether safe and efficient NTN delivery can be achieved through FUS-induced BBB opening via intravenous administration, and thus trigger the neuroregeneration cascade in the nigrostriatal pathway. After the optimization of FUS parameters and target locations in the murine brain, NTN bioavailability and downstream signaling were detected and characterized through immunostaining. FUS significantly enhanced the delivery of NTN compared with the direct injection technique, whereas triggering of the signaling cascade was detected downstream to the neuronal nuclei. These findings thus indicate the potential of the FUS method to mediate transport of proteins through the blood–brain barrier in a PD animal model.     

Reliability and Validity of the Spence Children’s Anxiety Scale for Parents in Mainland Chinese Children and Adolescents

This study examined the psychometric properties of the Spence Children’s Anxiety Scale for Parents (SCAS-P) in 1943 father-mother dyads and 1785 students. Results of confirmatory factor analyses for SCAS-P were in favour of the original model with six correlated factors. The internal consistency of SCAS-P was acceptable (α = .63–.91), and the test–retest reliability was acceptable (r = .46–.72). The convergent and divergent validity of SCAS-P was supported by significant correlations with an internalizing subscale to a greater extent than with an externalizing subscale. Congruent validity was supported by significant correlations between father and mother reports (r = .60–.71) and child and parent reports (r = .25–.42). Significant differences between community and clinical samples supported the discriminant validity. Adolescents showed higher anxiety levels than children, and girls showed higher anxiety levels than boys. Our findings suggest that the SCAS-P is a suitable parent instrument to measure child anxiety symptoms in Mainland Chinese children and adolescents.