Chemogenetic activation or inhibition of histaminergic neurons bidirectionally modulates recognition memory formation and retrieval in male and female mice.

Several lines of evidence demonstrate that the brain histaminergic system is fundamental for cognitive processes and the expression of memories. Here, we investigated the effect of acute silencing or activation of histaminergic neurons in the hypothalamic tuberomamillary nucleus (TMNHA neurons) in vivo in both sexes in an attempt to provide direct and causal evidence of the necessary role of these neurons in recognition memory formation and retrieval. To this end, we compared the performance of mice in two non-aversive and non-rewarded memory tests, the social and object recognition memory tasks, which are known to recruit different brain circuitries. To directly establish the impact of inactivation or activation of TMNHA neurons, we examined the effect of specific chemogenetic manipulations during the formation (acquisition/consolidation) or retrieval of recognition memories. We consistently found that acute chemogenetic silencing of TMNHA neurons disrupts the formation or retrieval of both social and object recognition memory in males and females. Conversely, acute chemogenetic activation of TMNHA neurons during training or retrieval extended social memory in both sexes and object memory in a sex-specific fashion. These results suggest that the formation or retrieval of recognition memory requires the tonic activity of histaminergic neurons and strengthen the concept that boosting the brain histaminergic system can promote the retrieval of apparently lost memories.

Pharmacological blockage of NOP receptors decreases ventral tegmental area dopamine neuronal activity through GABAB receptor-mediated mechanism.

The Nociceptin/Orphanin FQ (N/OFQ) peptide and its receptor NOP are highly expressed within several regions of the mesolimbic system, including the ventral tegmental area (VTA). Evidence indicates that the N/OFQ-NOP receptor system is involved in reward processing and historically it has been proposed that activation of NOP receptors attenuates the motivation for substances of abuse. However, recent findings demonstrated that drug self-administration and relapse to drug-seeking are also attenuated after administration of NOP receptor antagonists. Here, to shed light on the mechanisms through which NOP receptor blockers modulate these processes, we utilized ex vivo patch-clamp recordings to investigate the effect of the selective NOP receptor antagonist LY2817412 on VTA dopaminergic (DA) function in male rats. Results showed that, similar to the endogenous NOP receptor agonist N/OFQ, LY2817412 reduced the spontaneous basal firing discharge of VTA DA neurons. Consistently, we found that NOP receptors are expressed both in VTA DA and GABA cells and that LY2817412 slice perfusion increased GABA release onto VTA DA cells. Finally, in the attempt to dissect the role of postsynaptic and presynaptic NOP receptors, we tested the effect of N/OFQ and LY2817412 in the presence of GABA receptors blockers. Results showed that the effect of LY2817412 was abolished following pretreatment with GABABR, but not GABAAR, blockers. Conversely, inhibition of DA neuronal activity by N/OFQ was unaffected by blockade of GABA receptors. Altogether, these results suggest that both NOP receptor agonists and antagonists can decrease VTA DA neuronal activity, but through distinct mechanisms of action. The effect of NOP receptor antagonists occurs through a GABABR-mediated mechanism while NOP receptor agonists seem to act via a direct effect on VTA DA neurons.

Ethanol-induced AMPA alterations are mediated by mGLU5 receptors through miRNA upregulation in hippocampal slices.

Prenatal alcohol exposure (PAE) affects neuronal networks and brain development causing a range of physical, cognitive and behavioural disorders in newborns that persist into adulthood. The array of consequences associated with PAE can be grouped under the umbrella-term 'fetal alcohol spectrum disorders' (FASD). Unfortunately, there is no cure for FASD as the molecular mechanisms underlying this pathology are still unknown. We have recently demonstrated that chronic EtOH exposure, followed by withdrawal, induces a significant decrease in AMPA receptor (AMPAR) expression and function in developing hippocampus in vitro. Here, we explored the EtOH-dependent pathways leading to hippocampal AMPAR suppression. Organotypic hippocampal slices (2 days in cultures) were exposed to EtOH (150 mM) for 7 days followed by 24 h EtOH withdrawal. Then, the slices were analysed by means of RT-PCR for miRNA content, western blotting for AMPA and NMDA related-synaptic proteins expression in postsynaptic compartment and electrophysiology to record electrical properties from CA1 pyramidal neurons. We observed that EtOH induces a significant downregulation of postsynaptic AMPA and NMDA subunits and relative scaffolding protein expression and, accordingly, a decrease of AMPA-mediated neurotransmission. Simultaneously, we found that chronic EtOH induced-upregulation of miRNA 137 and 501-3p and decreased AMPA-mediated neurotransmission are prevented by application of the selective mGlu5 antagonist MPEP during EtOH withdrawal. Our data indicate mGlu5 via miRNA137 and 501-3p expression as key factors in the regulation of AMPAergic neurotransmission that may contribute, at least in part, to the pathogenesis of FASD.

Father Involvement and Cognitive Development in Early and Middle Childhood: A Systematic Review.

This systematic review aims to examine the existing literature concerning the association between father involvement and the development children's cognitive skills during early and middle childhood. Specifically, it analyzes: (1) how the number of researches developed across years; (2) which are the main socio-demographic characteristics of the samples; (3) which are the main focuses examined; and (4) which operational definitions were used to assess father involvement and children cognitive skills. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, the articles were searched through PubMed and EBSCO (PsycInfo, PsycArticles, Education Source, Social Sciences Abstract, Family Studies Abstracts, Gender Studies Database and CINAHL complete). The findings suggest that, although each research used a different operational definition of the father involvement construct, in recent years there was a wide and constant interest increase about this issue. Most of the empirical studies utilized quantitative methods, whereas relatively few used qualitative and only one mixed methods. As regards the analysis of socio-demographic characteristics of the samples there is a great evidence that most of them included biological and residential fathers: it may reflect that this type of sample is easier to recruit than non-residential and non-biological fathers. Regarding the socio-economic status and the ethnicity of families, the data highlighted how in recent years the literature on father involvement is starting to look at differences in ethnic and cultural backgrounds, in contrast to past researches. The findings revealed that the main focus is the impact of father involvement on children's cognitive skills and the most of the studies highlighted that it is positive and statistically significant. Regarding to the assessment of father involvement and children's cognitive skills, the literature is quite heterogeneous.

Twins' and Singletons' Linguistic Environment: A Systematic Review.

Background: Among twins, lower linguistic skills emerged when compared with singletons. Considering the association found between parental linguistic input and children's language development, exploring the differences between twins and singletons' linguistic environments could find variables that are potentially associated with the lower linguistic skills of twins. Aim: The current systematic review aims to analyze and systematize the existing literature focused on the comparison of twins' and singletons' linguistic environments within their first 3 years of life. Methodological issues (i.e., the procedure used to assess the linguistic environment, the coding of the linguistic environment's features, the computational method employed to assess the parental linguistic input, and participant characteristics) and differences found among twins and singletons regarding their linguistic environment (i.e., linguistic input quantity, linguistic input complexity, linguistic features of child-directed speech, parental responsiveness, and directiveness, joint attention, and book reading) were highlighted. Method: The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement was followed. Eligible studies were searched through EBSCO, PubMed, and Web of Science. From this search, 1,347 study results emerged, and 8 studies were included. Results: To our knowledge, this is the first systematic review focused on the comparison of twins' and singletons' linguistic environments. Differences between the groups were found in all of the included studies. Data against twins were generally identified regarding all the considered linguistic environment's features. However, conflicting results within and between the included studies emerged, mainly according to the computational method employed (i.e., twin moms value, twin direct dyadic value, twin direct dyadic + both value, and input directed toward both children simultaneously). Conclusion: The disadvantaged linguistic environment of twins is likely due to limited parental resources and demands associated with the management of two children of the same age. However, the limited and conflicting data found did not allow for a firm conclusion to be drawn on the differences in the twins' and singletons' linguistic environments. Further studies on the topic are needed.

Intimate Partner Violence in the Golden Age: Systematic Review of Risk and Protective Factors.

Intimate partner violence (IPV) is identifiable as a major public health concern worldwide. The international literature highlights how this phenomenon is complex and transversal to all age groups. While the global population is becoming older, the scientific research about risk and protective factors related to IPV in the golden age is diverse, and the different findings of the various studies have not been systematized so far. Thus, in this systematic review, we aim to analyze the scientific studies that investigate the risk and the protective factors of violent dynamics between elderly couples. From the perspective of the theoretical frameworks and the methodological approaches used, we present the main conceptual themes that emerge. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, we review the articles that report the analyses of protective and risk factors of IPV perpetration. Our results indicate social support, help-seeking behavior, and the availability of community-based services addressing the issues of abuse as the main protective factors. The risk factors are related to economic conditions, belonging to an ethnic minority, cognitive or physical impairment, other conditions associated with cultural background and relational dynamics, such as intrapartner dependence and intergenerational transmission of violence and trauma, and caregiving stress. We discuss possible future directions of research to improve the understanding of IPV in the elderly population and the implications for the development of intervention policies at preventive and supportive levels.