scholarly journals The neural basis of tadpole transport in poison frogs

2019 ◽  
Author(s):  
Eva K. Fischer ◽  
Alexandre B. Roland ◽  
Nora A. Moskowitz ◽  
Elicio E. Tapia ◽  
Kyle Summers ◽  
...  
Keyword(s):  
Parental Care ◽  
Molecular Mechanisms ◽  
Neural Induction ◽  
Brain Regions ◽  
Evolutionary Significance ◽  
Neural Basis ◽  
Parental Behaviour ◽  
Poison Frogs ◽  
Care Patterns ◽  
Species Specific

AbstractParental care has evolved repeatedly and independently across animals. While the ecological and evolutionary significance of parental behaviour is well recognized, underlying mechanisms remain poorly understood. We took advantage of behavioural diversity across closely related species of South American poison frogs (Family Dendrobatidae) to identify neural correlates of parental behaviour shared across sexes and species. We characterized differences in neural induction, gene expression in active neurons, and activity of specific neuronal types in three species with distinct parental care patterns: male uniparental, female uniparental, and biparental. We identified the medial pallium and preoptic area as core brain regions associated with parental care, independent of sex and species. Identification of neurons active during parental care confirms a role for neuropeptides associated with care in other vertebrates as well as identifying novel candidates. Our work is the first to explore neural and molecular mechanisms of parental care in amphibians and highlights the potential for mechanistic studies in closely related but behaviourally variable species to build a more complete understanding of how shared principles and species-specific diversity govern parental care and other social behaviour.

scholarly journals The neural basis of tadpole transport in poison frogs

2019 ◽  
Vol 286 (1907) ◽  
pp. 20191084 ◽  
Author(s):  
Eva K. Fischer ◽  
Alexandre B. Roland ◽  
Nora A. Moskowitz ◽  
Elicio E. Tapia ◽  
Kyle Summers ◽  
...  
Keyword(s):  
Parental Care ◽  
Molecular Mechanisms ◽  
Neural Induction ◽  
Brain Regions ◽  
Evolutionary Significance ◽  
Neural Basis ◽  
Parental Behaviour ◽  
Poison Frogs ◽  
Care Patterns ◽  
Species Specific

Parental care has evolved repeatedly and independently across animals. While the ecological and evolutionary significance of parental behaviour is well recognized, underlying mechanisms remain poorly understood. We took advantage of behavioural diversity across closely related species of South American poison frogs (Family Dendrobatidae) to identify neural correlates of parental behaviour shared across sexes and species. We characterized differences in neural induction, gene expression in active neurons and activity of specific neuronal types in three species with distinct care patterns: male uniparental, female uniparental and biparental. We identified the medial pallium and preoptic area as core brain regions associated with parental care, independent of sex and species. The identification of neurons active during parental care confirms a role for neuropeptides associated with care in other vertebrates as well as identifying novel candidates. Our work is the first to explore neural and molecular mechanisms of parental care in amphibians and highlights the potential for mechanistic studies in closely related but behaviourally variable species to help build a more complete understanding of how shared principles and species-specific diversity govern parental care and other social behaviour.

scholarly journals Understanding the Effects of General Anesthetics on Cortical Network Activity Using Ex Vivo Preparations

2019 ◽  
Vol 130 (6) ◽  
pp. 1049-1063 ◽  
Author(s):  
Logan J. Voss ◽  
Paul S. García ◽  
Harald Hentschke ◽  
Matthew I. Banks
Keyword(s):  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Brain Slices ◽  
Brain Regions ◽  
Cortical Network ◽  
Network Activity ◽  
Common Mechanism ◽  
General Anesthetics ◽  
Neural Basis

Abstract General anesthetics have been used to ablate consciousness during surgery for more than 150 yr. Despite significant advances in our understanding of their molecular-level pharmacologic effects, comparatively little is known about how anesthetics alter brain dynamics to cause unconsciousness. Consequently, while anesthesia practice is now routine and safe, there are many vagaries that remain unexplained. In this paper, the authors review the evidence that cortical network activity is particularly sensitive to general anesthetics, and suggest that disruption to communication in, and/or among, cortical brain regions is a common mechanism of anesthesia that ultimately produces loss of consciousness. The authors review data from acute brain slices and organotypic cultures showing that anesthetics with differing molecular mechanisms of action share in common the ability to impair neurophysiologic communication. While many questions remain, together, ex vivo and in vivo investigations suggest that a unified understanding of both clinical anesthesia and the neural basis of consciousness is attainable.

scholarly journals Mechanisms of convergent egg-provisioning in poison frogs

2019 ◽  
Author(s):  
Eva K. Fischer ◽  
Alexandre B. Roland ◽  
Nora A. Moskowitz ◽  
Charles Vidoudez ◽  
Ndimbintsoa Ranaivorazo ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Field Studies ◽  
Brain Regions ◽  
Chemical Defenses ◽  
Lateral Septum ◽  
Neuron Activity ◽  
South American ◽  
Poison Frogs ◽  
Provisioning Behavior ◽  
Maternal Provisioning

AbstractParental provisioning of offspring with physiological products occurs in many animals. Within amphibians, maternal provisioning has evolved multiple times, including in South American dendrobatid and Malagasy mantellid poison frogs. In some of these species, mothers feed unfertilized eggs to their developing tadpoles for several months until tadpoles complete metamorphosis. We conducted field studies in Ecuador and Madagascar to ask whether convergence at the behavioral level provides similar benefits to offspring and whether nursing behavior relies on shared neural mechanisms across frogs and vertebrates more broadly. At an ecological level, we found that nursing allows poison frog mothers to provide chemical defenses to their tadpoles in both species. At the level of brain regions, nursing behavior was associated with increased neural activity in the lateral septum and preoptic area in both species, demonstrating recruitment of shared brain regions in the convergent evolution of maternal care within frogs and across vertebrates. In contrast at a molecular level, only mantellids showed increased oxytocin neuron activity akin to that in nursing mammals. Taken together, our findings demonstrate that convergently evolved maternal provisioning behavior provides similar benefits to offspring and relies on similar brain regions. However, the molecular mechanisms underlying the convergence in nursing behavior may be different, suggesting evolutionary versatility in the mechanisms promoting maternal behavior.

scholarly journals Brain transcriptomic changes in Japanese quail reveal a role for neurotensin in avian parental care

2020 ◽  
Author(s):  
Patricia C. Lopes ◽  
Robert de Bruijn
Keyword(s):  
Parental Care ◽  
Japanese Quail ◽  
Mammalian Species ◽  
Bird Species ◽  
Brain Regions ◽  
Maternal Behaviour ◽  
Neural Basis ◽  
Transcriptomic Changes ◽  
Parental Responses ◽  
The Brain

AbstractFor many species, parental care critically affects offspring survival. But what drives animals to display parental behaviours towards young? In mammals, pregnancy-induced physiological transformations seem key in preparing the neural circuits that lead towards attraction (and reduced-aggression) to young. Beyond mammalian maternal behaviour, knowledge of the neural mechanisms that underlie parental care is severely lacking. We took advantage of a domesticated bird species, the Japanese quail, for which parental behaviour towards chicks can be induced through a sensitization procedure, a process that is not effective in all animals. We used the variation in parental responses to study neural transcriptomic changes associated with the sensitization procedure itself, with the outcome of the procedure (i.e., presence of parental behaviours) and with spontaneous parental care (i.e., in the absence of sensitization). Out of the brain regions studied, we found that most differences in gene expression were located in the hypothalamus. Our results highlight several molecular pathways that may contribute to the modulation of avian parental care. We identified one gene, neurotensin, that was previously only demonstrated to be causally associated with parental care in mammals. Our work opens new avenues of research into understanding the neural basis of parental care in non-mammalian species.

scholarly journals Aerobic Exercise Induces Alternative Splicing of Neurexins in Frontal Cortex

2021 ◽  
Vol 6 (2) ◽  
pp. 48
Author(s):  
Elisa Innocenzi ◽  
Ida Cariati ◽  
Emanuela De Domenico ◽  
Erika Tiberi ◽  
Giovanna D’Arcangelo ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Aerobic Exercise ◽  
Frontal Cortex ◽  
Molecular Mechanisms ◽  
Splice Variants ◽  
Brain Regions ◽  
Synaptic Function ◽  
Molecular Changes ◽  
Beneficial Effects ◽  
The Impact

Aerobic exercise (AE) is known to produce beneficial effects on brain health by improving plasticity, connectivity, and cognitive functions, but the underlying molecular mechanisms are still limited. Neurexins (Nrxns) are a family of presynaptic cell adhesion molecules that are important in synapsis formation and maturation. In vertebrates, three-neurexin genes (NRXN1, NRXN2, and NRXN3) have been identified, each encoding for α and β neurexins, from two independent promoters. Moreover, each Nrxns gene (1–3) has several alternative exons and produces many splice variants that bind to a large variety of postsynaptic ligands, playing a role in trans-synaptic specification, strength, and plasticity. In this study, we investigated the impact of a continuous progressive (CP) AE program on alternative splicing (AS) of Nrxns on two brain regions: frontal cortex (FC) and hippocampus. We showed that exercise promoted Nrxns1–3 AS at splice site 4 (SS4) both in α and β isoforms, inducing a switch from exon-excluded isoforms (SS4−) to exon-included isoforms (SS4+) in FC but not in hippocampus. Additionally, we showed that the same AE program enhanced the expression level of other genes correlated with synaptic function and plasticity only in FC. Altogether, our findings demonstrated the positive effect of CP AE on FC in inducing molecular changes underlying synaptic plasticity and suggested that FC is possibly a more sensitive structure than hippocampus to show molecular changes.

scholarly journals Developmental cannabidiol exposure increases anxiety and modifies genome-wide brain DNA methylation in adult female mice

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Nicole M. Wanner ◽  
Mathia Colwell ◽  
Chelsea Drown ◽  
Christopher Faulk
Keyword(s):  
Dna Methylation ◽  
Molecular Mechanisms ◽  
Coat Color ◽  
Brain Regions ◽  
Functional Enrichment ◽  
Positive Effects ◽  
Genome Wide ◽  
Nulliparous Female ◽  
The Impact ◽  
The Brain

Abstract Background Use of cannabidiol (CBD), the primary non-psychoactive compound found in cannabis, has recently risen dramatically, while relatively little is known about the underlying molecular mechanisms of its effects. Previous work indicates that direct CBD exposure strongly impacts the brain, with anxiolytic, antidepressant, antipsychotic, and other effects being observed in animal and human studies. The epigenome, particularly DNA methylation, is responsive to environmental input and can direct persistent patterns of gene regulation impacting phenotype. Epigenetic perturbation is particularly impactful during embryogenesis, when exogenous exposures can disrupt critical resetting of epigenetic marks and impart phenotypic effects lasting into adulthood. The impact of prenatal CBD exposure has not been evaluated; however, studies using the psychomimetic cannabinoid Δ9-tetrahydrocannabinol (THC) have identified detrimental effects on psychological outcomes in developmentally exposed adult offspring. We hypothesized that developmental CBD exposure would have similar negative effects on behavior mediated in part by the epigenome. Nulliparous female wild-type Agouti viable yellow (Avy) mice were exposed to 20 mg/kg CBD or vehicle daily from two weeks prior to mating through gestation and lactation. Coat color shifts, a readout of DNA methylation at the Agouti locus in this strain, were measured in F1 Avy/a offspring. Young adult F1 a/a offspring were then subjected to tests of working spatial memory and anxiety/compulsive behavior. Reduced-representation bisulfite sequencing was performed on both F0 and F1 cerebral cortex and F1 hippocampus to identify genome-wide changes in DNA methylation for direct and developmental exposure, respectively. Results F1 offspring exposed to CBD during development exhibited increased anxiety and improved memory behavior in a sex-specific manner. Further, while no significant coat color shift was observed in Avy/a offspring, thousands of differentially methylated loci (DMLs) were identified in both brain regions with functional enrichment for neurogenesis, substance use phenotypes, and other psychologically relevant terms. Conclusions These findings demonstrate for the first time that despite positive effects of direct exposure, developmental CBD is associated with mixed behavioral outcomes and perturbation of the brain epigenome.

scholarly journals Sialylated human milk oligosaccharides program cognitive development through a non-genomic transmission mode

2021 ◽  
Author(s):  
Jonas Hauser ◽  
Edoardo Pisa ◽  
Alejandro Arias Vásquez ◽  
Flavio Tomasi ◽  
Alice Traversa ◽  
...  
Keyword(s):  
Cognitive Development ◽  
Gut Microbiota ◽  
Human Milk ◽  
Molecular Mechanisms ◽  
Brain Regions ◽  
Nervous System Development ◽  
Bioactive Molecules ◽  
Human Milk Oligosaccharides ◽  
Milk Oligosaccharides ◽  
Eye Opening

AbstractBreastmilk contains bioactive molecules essential for brain and cognitive development. While sialylated human milk oligosaccharides (HMOs) have been implicated in phenotypic programming, their selective role and underlying mechanisms remained elusive. Here, we investigated the long-term consequences of a selective lactational deprivation of a specific sialylated HMO in mice. We capitalized on a knock-out (KO) mouse model (B6.129-St6gal1tm2Jxm/J) lacking the gene responsible for the synthesis of sialyl(alpha2,6)lactose (6′SL), one of the two sources of sialic acid (Neu5Ac) to the lactating offspring. Neu5Ac is involved in the formation of brain structures sustaining cognition. To deprive lactating offspring of 6′SL, we cross-fostered newborn wild-type (WT) pups to KO dams, which provide 6′SL-deficient milk. To test whether lactational 6′SL deprivation affects cognitive capabilities in adulthood, we assessed attention, perseveration, and memory. To detail the associated endophenotypes, we investigated hippocampal electrophysiology, plasma metabolomics, and gut microbiota composition. To investigate the underlying molecular mechanisms, we assessed gene expression (at eye-opening and in adulthood) in two brain regions mediating executive functions and memory (hippocampus and prefrontal cortex, PFC). Compared to control mice, WT offspring deprived of 6′SL during lactation exhibited consistent alterations in all cognitive functions addressed, hippocampal electrophysiology, and in pathways regulating the serotonergic system (identified through gut microbiota and plasma metabolomics). These were associated with a site- (PFC) and time-specific (eye-opening) reduced expression of genes involved in central nervous system development. Our data suggest that 6′SL in maternal milk adjusts cognitive development through a short-term upregulation of genes modulating neuronal patterning in the PFC.

scholarly journals Npas4a expression in the teleost forebrain is associated with stress coping style differences in fear learning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthew R. Baker ◽  
Ryan Y. Wong
Keyword(s):  
Neural Plasticity ◽  
Coping Style ◽  
Molecular Mechanisms ◽  
Conditioned Fear ◽  
Coping Styles ◽  
Brain Regions ◽  
Contextual Fear Conditioning ◽  
Fear Learning ◽  
Stress Coping ◽  
Contextual Fear

AbstractLearning to anticipate potentially dangerous contexts is an adaptive behavioral response to coping with stressors. An animal’s stress coping style (e.g. proactive–reactive axis) is known to influence how it encodes salient events. However, the neural and molecular mechanisms underlying these stress coping style differences in learning are unknown. Further, while a number of neuroplasticity-related genes have been associated with alternative stress coping styles, it is unclear if these genes may bias the development of conditioned behavioral responses to stressful stimuli, and if so, which brain regions are involved. Here, we trained adult zebrafish to associate a naturally aversive olfactory cue with a given context. Next, we investigated if expression of two neural plasticity and neurotransmission-related genes (npas4a and gabbr1a) were associated with the contextual fear conditioning differences between proactive and reactive stress coping styles. Reactive zebrafish developed a stronger conditioned fear response and showed significantly higher npas4a expression in the medial and lateral zones of the dorsal telencephalon (Dm, Dl), and the supracommissural nucleus of the ventral telencephalon (Vs). Our findings suggest that the expression of activity-dependent genes like npas4a may be differentially expressed across several interconnected forebrain regions in response to fearful stimuli and promote biases in fear learning among different stress coping styles.

scholarly journals An Exon-Based Comparative Variant Analysis Pipeline to Study the Scale and Role of Frameshift and Nonsense Mutation in the Human-Chimpanzee Divergence

2009 ◽  
Vol 2009 ◽  
pp. 1-19 ◽  
Author(s):  
GongXin Yu
Keyword(s):  
Molecular Mechanisms ◽  
Inflammatory Diseases ◽  
Cell Lineage ◽  
Nonsense Mutations ◽  
Less Is More ◽  
Sequencing Errors ◽  
Evolutionary Force ◽  
Variant Analysis ◽  
Species Specific

Chimpanzees and humans are closely related but differ in many deadly human diseases and other characteristics in physiology, anatomy, and pathology. In spite of decades of extensive research, crucial questions about the molecular mechanisms behind the differences are yet to be understood. Here I reportExonVar, a novel computational pipeline forExon-based human-chimpanzee comparativeVariant analysis. The objective is to comparatively analyze mutations specifically those that caused the frameshift and nonsense mutations and to assess their scale and potential impacts on human-chimpanzee divergence. Genomewide analysis of human and chimpanzee exons withExonVaridentified a number of species-specific, exon-disrupting mutations in chimpanzees but much fewer in humans. Many were found on genes involved in important biological processes such as T cell lineage development, the pathogenesis of inflammatory diseases, and antigen induced cell death. A “less-is-more” model was previously established to illustrate the role of the gene inactivation and disruptions during human evolution. Here this analysis suggested a different model where the chimpanzee-specific exon-disrupting mutations may act as additional evolutionary force that drove the human-chimpanzee divergence. Finally, the analysis revealed a number of sequencing errors in the chimpanzee and human genome sequences and further illustrated that they could be corrected without resequencing.

scholarly journals Embryo-induced transcriptome changes in bovine endometrium reveal species-specific and common molecular markers of uterine receptivity

Reproduction ◽  
2006 ◽  
Vol 132 (2) ◽  
pp. 319-331 ◽  
Author(s):  
Stefan Bauersachs ◽  
Susanne E Ulbrich ◽  
Karin Gross ◽  
Susanne E M Schmidt ◽  
Heinrich H D Meyer ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Molecular Mechanisms ◽  
Cdna Array ◽  
Early Embryo ◽  
Cdna Libraries ◽  
Control Group ◽  
Regulation Of Transcription ◽  
Uterine Receptivity ◽  
Subtracted Cdna Libraries ◽  
Species Specific

The endometrium plays a central role among the reproductive tissues in the context of early embryo–maternal communication and pregnancy. This study investigated transcriptome profiles of endometrium samples from day 18 pregnant vs non-pregnant heifers to get insight into the molecular mechanisms involved in conditioning the endometrium for embryo attachment and implantation. Using a combination of subtracted cDNA libraries and cDNA array hybridisation, 109 mRNAs with at least twofold higher abundance in endometrium of pregnant animals and 70 mRNAs with higher levels in the control group were identified. Among the mRNAs with higher abundance in pregnant animals, at least 41 are already described as induced by interferons. In addition, transcript levels of many new candidate genes involved in the regulation of transcription, cell adhesion, modulation of the maternal immune system and endometrial remodelling were found to be increased. The different expression level was confirmed with real-time PCR for nine genes. Localisation of mRNA expression in the endometrium was shown byin situhybridisation forAGRN,LGALS3BP,LGALS9,USP18,PARP12andBST2. A comparison with similar studies in humans, mice, and revealed species-specific and common molecular markers of uterine receptivity.

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