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Laboratory Animals Jun 2024Animal welfare has evolved during the past decades to improve not only the quality of life of laboratory rodents but also the quality and reproducibility of scientific...
Animal welfare has evolved during the past decades to improve not only the quality of life of laboratory rodents but also the quality and reproducibility of scientific investigations. Bibliometric analysis has become an important tool to complete the current knowledge with academic databases. Our objective was to investigate whether scientific research on cannibalism/infanticide is connected with maternal aggression towards the offspring in laboratory rodents. To carry out our research, we performed a specific search for published articles on each concept. Results were analyzed in the open-source environment RStudio with the package Bibliometrix. We obtained 253 and 134 articles for the first search (cannibalism/infanticide) and the second search (maternal aggression towards the pups) respectively. We observed that the interest in infanticide/cannibalism started in the 1950s, while researchers started showing interest in maternal aggression towards the pups 30 years later. Our analyses indicated that maternal aggression had better citations in scientific literature. In addition, although our results showed some common features (e.g. oxytocin or medial preoptic area in the brain), we observed a gap between cannibalism/infanticide and maternal aggression towards the pups with only 14 published articles in common for both the searches. Therefore, we recommend researchers to combine both concepts in further investigations in the context of cannibalism for better dissemination and higher impact in laboratory rodents' welfare research.
Topics: Animals; Cannibalism; Aggression; Bibliometrics; Female; Maternal Behavior; Rats; Animals, Laboratory; Rodentia; Animal Welfare; Mice; Behavior, Animal
PubMed: 38353042
DOI: 10.1177/00236772231192030 -
BioRxiv : the Preprint Server For... Jan 2024Sexual differentiation of the brain occurs in all major vertebrate lineages but is not well understood at a molecular and cellular level. Unlike most vertebrates,...
Sexual differentiation of the brain occurs in all major vertebrate lineages but is not well understood at a molecular and cellular level. Unlike most vertebrates, sex-changing fishes have the remarkable ability to change reproductive sex during adulthood in response to social stimuli, offering a unique opportunity to understand mechanisms by which the nervous system can initiate and coordinate sexual differentiation. This study explores sexual differentiation of the forebrain using single nucleus RNA-sequencing in the anemonefish , producing the first cellular atlas of a sex-changing brain. We uncover extensive sex differences in cell type-specific gene expression, relative proportions of cells, baseline neuronal excitation, and predicted inter-neuronal communication. Additionally, we identify the cholecystokinin, galanin, and estrogen systems as central molecular axes of sexual differentiation. Supported by these findings, we propose a model of neurosexual differentiation in the conserved vertebrate social decision-making network spanning multiple subtypes of neurons and glia, including neuronal subpopulations within the preoptic area that are positioned to regulate gonadal differentiation. This work deepens our understanding of sexual differentiation in the vertebrate brain and defines a rich suite of molecular and cellular pathways that differentiate during adult sex change in anemonefish.
PubMed: 38352560
DOI: 10.1101/2024.01.29.577753 -
Nature Neuroscience Apr 2024Social behaviors often consist of a motivational phase followed by action. Here we show that neurons in the ventromedial hypothalamus ventrolateral area (VMHvl) of mice...
Social behaviors often consist of a motivational phase followed by action. Here we show that neurons in the ventromedial hypothalamus ventrolateral area (VMHvl) of mice encode the temporal sequence of aggressive motivation to action. The VMHvl receives local inhibitory input (VMHvl shell) and long-range input from the medial preoptic area (MPO) with functional coupling to neurons with specific temporal profiles. Encoding models reveal that during aggression, VMHvl shell activity peaks at the start of an attack, whereas activity from the MPO-VMHvl input peaks at specific interaction endpoints. Activation of the MPO-VMHvl input promotes and prolongs a low motivation state, whereas activation of VMHvl shell results in action-related deficits, acutely terminating attack. Moreover, stimulation of MPO-VMHvl input is positively valenced and anxiolytic. Together, these data demonstrate how distinct inhibitory inputs to the hypothalamus can independently gate the motivational and action phases of aggression through a single locus of control.
Topics: Mice; Animals; Aggression; Motivation; Social Behavior; Hypothalamus; Neurons
PubMed: 38347201
DOI: 10.1038/s41593-023-01563-6 -
Hormones and Behavior Nov 2023Gonadal hormone actions through androgen receptor (AR) and estrogen receptor alpha (ERα) regulate sex differences in hypothalamic-pituitary-adrenal (HPA) axis...
Gonadal hormone actions through androgen receptor (AR) and estrogen receptor alpha (ERα) regulate sex differences in hypothalamic-pituitary-adrenal (HPA) axis responsivity and stress-related behaviors. Here we tested whether corticotropin releasing factor (CRF) expressing neurons, which are widely known to regulate neuroendocrine and behavioral stress responses, co-express AR and ERα as a potential mechanism for gonadal hormone regulation of these responses. Using Crh-IRES-Cre::Ai9 reporter mice we report high co-localization of AR in CRF neurons within the medial preoptic area (MPOA), bed nucleus of the stria terminalis (BST), medial amygdala (MeA), and ventromedial hypothalamus (VMH), moderate levels within the central amygdala (CeA) and low levels in the paraventricular hypothalamus (PVN). Sex differences in CRF/AR co-expression were found in the principal nucleus of the BST (BSTmpl), CeA, MeA, and VMH (males>females). CRF co-localization with ERα was generally lower relative to AR co-localization. However, high co-expression was found within the MPOA, AVPV, and VMH, with moderate co-expression in the arcuate nucleus (ARC), BST, and MeA and low levels in the PVN and CeA. Sex differences in CRF/ERα co-localization were found in the BSTmpl and PVN (males>females). Finally, we assessed neural activation of CRF neurons in restraint-stressed mice and found greater CRF/c-Fos co-expression in females in the BSTmpl and periaqueductal gray, while co-expression was higher in males within the ARC and dorsal CA1. Given the known role of CRF in regulating behavioral stress responses and the HPA axis, AR/ERα co-expression and sex-specific activation of CRF cell groups indicate potential mechanisms for modulating sex differences in these functions.
Topics: Mice; Female; Male; Animals; Corticotropin-Releasing Hormone; Estrogen Receptor alpha; Hypothalamo-Hypophyseal System; Sex Characteristics; Receptors, Androgen; Pituitary-Adrenal System; Receptors, Corticotropin-Releasing Hormone; Proto-Oncogene Proteins c-fos; Neurons; Gonadal Hormones; Paraventricular Hypothalamic Nucleus
PubMed: 38344954
DOI: 10.1016/j.yhbeh.2023.105448 -
Psychoneuroendocrinology May 2024Perinatal testosterone, or its metabolite estradiol, organize the brain toward a male phenotype. Male rodents with insufficient testosterone during this period fail to...
Cohabitation with receptive females under D2-type agonism in adulthood restores partner preference and brain dimorphism in the SDN-POA following neonatal gonadectomy in male rats.
Perinatal testosterone, or its metabolite estradiol, organize the brain toward a male phenotype. Male rodents with insufficient testosterone during this period fail to display sexual behavior and partner preference for receptive females in adulthood. However, cohabitation with non-reproductive conspecifics under the influence of a D2 agonist facilitates the expression of conditioned partner preference via Pavlovian learning in gonadally intact male rats. In the present experiment, three groups of neonatal PD1 males (N = 12/group) were either gonadectomized (GDX), sham-GDX, or left intact and evaluated for social preferences and sexual behaviors as adults. We then examined whether the effects of GDX could be reversed by conditioning the males via cohabitation with receptive females under the effects of the D2 agonist quinpirole (QNP) or saline, along with the size of some brain regions, such as the sexually dimorphic nucleus of the preoptic area (SDN-POA), suprachiasmatic nucleus (SCN), posterior dorsal medial amygdala (MeApd) and ventromedial hypothalamus (VMH). Results indicated that neonatal GDX resulted in the elimination of male-typical sexual behavior, an increase in same-sex social preference, and a reduction of the area of the SDN-POA. However, GDX-QNP males that underwent exposure to receptive females in adulthood increased their social preference for females and recovered the size in the SDN-POA. Although neonatal GDX impairs sexual behavior and disrupts partner preference and brain dimorphism in adult male rats, Pavlovian conditioning under enhanced D2 agonism ameliorates the effects on social preference and restores brain dimorphism in the SDN-POA without testosterone.
Topics: Pregnancy; Rats; Animals; Male; Female; Preoptic Area; Sex Characteristics; Brain; Quinpirole; Castration; Testosterone
PubMed: 38342055
DOI: 10.1016/j.psyneuen.2024.106988 -
Frontiers in Neural Circuits 2023Parental care plays a crucial role in the physical and mental well-being of mammalian offspring. Although sexually naïve male mice, as well as certain strains of female... (Review)
Review
Parental care plays a crucial role in the physical and mental well-being of mammalian offspring. Although sexually naïve male mice, as well as certain strains of female mice, display aggression toward pups, they exhibit heightened parental caregiving behaviors as they approach the time of anticipating their offspring. In this Mini Review, I provide a concise overview of the current understanding of distinct limbic neural types and their circuits governing both aggressive and caregiving behaviors toward infant mice. Subsequently, I delve into recent advancements in the understanding of the molecular, cellular, and neural circuit mechanisms that regulate behavioral plasticity during the transition to parenthood, with a specific focus on the sex steroid hormone estrogen and neural hormone oxytocin. Additionally, I explore potential sex-related differences and highlight some critical unanswered questions that warrant further investigation.
Topics: Humans; Mice; Male; Animals; Female; Paternal Behavior; Aggression; Oxytocin; Mammals
PubMed: 38298741
DOI: 10.3389/fncir.2023.1340497 -
The Journal of Comparative Neurology Jan 2024The torus semicircularis (TS) of teleosts is a key midbrain center of the lateral line and acoustic sensory systems. To characterize the TS in adult zebrafish, we...
The torus semicircularis (TS) of teleosts is a key midbrain center of the lateral line and acoustic sensory systems. To characterize the TS in adult zebrafish, we studied their connections using the carbocyanine tracers applied to the TS and to other related nuclei and tracts. Two main TS nuclei, central and ventrolateral, were differentiable by their afferent connections. From central TS, (TSc) numerous toropetal cells were labeled bilaterally in several primary octaval nuclei (anterior, magnocellular, descending, and posterior octaval nuclei), in the secondary octaval nucleus, in the caudal octavolateralis nucleus, and in the perilemniscular region. In the midbrain, numerous toropetal cells were labeled in the contralateral TSc. In the diencephalon, toropetal cells labeled from the TSc were observed ipsilaterally in the medial prethalamic nucleus and the periventricular posterior tubercle nucleus. TSc toropetal neurons were also labeled bilaterally in the hypothalamic anterior tuberal nucleus (ATN) and ipsilaterally in the parvicellular preoptic nucleus but not in the telencephalon. Tracer application to the medial octavolateralis nucleus revealed contralateral projections to the ventrolateral TS (TSvl), whereas tracer application to the secondary octaval nucleus labeled fibers bilaterally in TSc and neurons in rostral TSc. The TSc sends ascending fibers to the ipsilateral lateral preglomerular region that, in turn, projects to the pallium. Application of DiI to the optic tectum labeled cells and fibers in the TSvl, whereas application of DiI to the ATN labeled cells and fibers in the TSc. These results reveal that the TSvl and TSc are mainly related with the mechanosensory lateral line and acoustic centers, respectively, and that they show different higher order connections.
Topics: Animals; Zebrafish; Neurons; Acoustics; Arcuate Nucleus of Hypothalamus; Superior Colliculi
PubMed: 38289191
DOI: 10.1002/cne.25586 -
Brain Sciences Jan 2024Transcranial direct current stimulation (tDCS) is acknowledged for its non-invasive modulation of neuronal activity in psychiatric disorders. However, its application in...
Transcranial direct current stimulation (tDCS) is acknowledged for its non-invasive modulation of neuronal activity in psychiatric disorders. However, its application in insomnia research yields varied outcomes depending on different tDCS types and patient conditions. Our primary objective is to elucidate its efficiency and uncover the underlying mechanisms in insomnia treatment. We hypothesized that anodal prefrontal cortex stimulation activates glutamatergic projections from the infralimbic cortex (IL) to the ventrolateral preoptic area (VLPO) to promote sleep. After administering 0.06 mA of electrical currents for 8 min, our results indicate significant non-rapid eye movement (NREM) enhancement in naïve mice within the initial 3 h post-stimulation, persisting up to 16-24 h. In the insomnia group, tDCS enhanced NREM sleep bout numbers during acute stress response and improved NREM and REM sleep duration in subsequent acute insomnia. Sleep quality, assessed through NREM delta powers, remains unaffected. Interference of the IL-VLPO pathway, utilizing designer receptors exclusively activated by designer drugs (DREADDs) with the cre-DIO system, partially blocked tDCS's sleep improvement in stress-induced insomnia. This study elucidated that the activation of the IL-VLPO pathway mediates tDCS's effect on stress-induced insomnia. These findings support the understanding of tDCS effects on sleep disturbances, providing valuable insights for future research and clinical applications in sleep therapy.
PubMed: 38275525
DOI: 10.3390/brainsci14010105 -
Hydrogen-rich water improves sleep consolidation and enhances forebrain neuronal activation in mice.Sleep Advances : a Journal of the Sleep... 2024Sleep loss contributes to various health issues and impairs neurological function. Molecular hydrogen has recently gained popularity as a nontoxic ergogenic and health...
STUDY OBJECTIVES
Sleep loss contributes to various health issues and impairs neurological function. Molecular hydrogen has recently gained popularity as a nontoxic ergogenic and health promoter. The effect of molecular hydrogen on sleep and sleep-related neural systems remains unexplored. This study investigates the impact of hydrogen-rich water (HRW) on sleep behavior and neuronal activation in sleep-deprived mice.
METHODS
Adult C57BL/6J mice were implanted with electroencephalography (EEG) and electromyography (EMG) recording electrodes and given HRW (0.7-1.4 mM) or regular water for 7 days ad libitum. Sleep-wake cycles were recorded under baseline conditions and after acute sleep loss. Neuronal activation in sleep- and wake-related regions was assessed using cFos immunostaining.
RESULTS
HRW increased sleep consolidation in undisturbed mice and increased non-rapid-eye movement and rapid-eye-movement sleep amount in sleep-deprived mice. HRW also decreased the average amount of time for mice to fall asleep after light onset. Neuronal activation in the lateral septum, medial septum, ventrolateral preoptic area, and median preoptic area was significantly altered in all mice treated with HRW.
CONCLUSIONS
HRW improves sleep consolidation and increases neuronal activation in sleep-related brain regions. It may serve as a simple, effective treatment to improve recovery after sleep loss.
PubMed: 38264142
DOI: 10.1093/sleepadvances/zpad057 -
Development, Growth & Differentiation Feb 2024Nuclear receptor subfamily 2 group F (Nr2f) proteins are essential for brain development in mice, but little is known about their precise roles and their evolutionary...
Nuclear receptor subfamily 2 group F (Nr2f) proteins are essential for brain development in mice, but little is known about their precise roles and their evolutionary diversification. In the present study, the expression patterns of major nr2f genes (nr2f1a, nr2f1b, and nr2f2) during early brain development were investigated in zebrafish. Comparisons of their expression patterns revealed similar but temporally and spatially distinct patterns after early somite stages in the brain. Frameshift mutations in the three nr2f genes, achieved using the CRISPR/Cas9 method, resulted in a smaller telencephalon and smaller eyes in the nr2f1a mutants; milder forms of those defects were present in the nr2f1b and nr2f2 mutants. Acridine orange staining revealed enhanced cell death in the brain and/or eyes in all nr2f homozygous mutants. The expression of regional markers in the brain did not suggest global defects in brain regionalization; however, shha expression in the preoptic area and hypothalamus, as well as fgf8a expression in the anterior telencephalon, was disturbed in nr2f1a and nr2f1b mutants, potentially leading to a defective telencephalon. Specification of the retina and optic stalk was also significantly affected. The overexpression of nr2f1b by injection of mRNA disrupted the anterior brain at a high dose, and the expression of pax6a in the eyes and fgf8a in the telencephalon at a low dose. The results of these loss- and gain-of-function approaches showed that nr2f genes regulate the development of the telencephalon and eyes in zebrafish embryos.
Topics: Animals; Mice; Brain; Eye; Gene Expression Regulation, Developmental; Telencephalon; Zebrafish; Zebrafish Proteins; Nuclear Receptor Subfamily 1, Group F, Member 2; Orphan Nuclear Receptors
PubMed: 38263801
DOI: 10.1111/dgd.12912