Biology subjects

Nomoto, K.

Publications and source records attributed to Nomoto, K..

8 recordsLinked to original sources

bioRxiv2023

Beacon-based sleep status and physical activity monitoring in humans.

One out of every five people in Japan is dissatisfied with their sleep and various diseases caused by lack of exercise have been pointed out, but there are few effective remedies for these problems. In this study, we aimed to develop a simple method for measuring behavioral sleep patterns and physical activity using a beacon accelerometer wirelessly connected with a smartphone. A sleep prediction model was created comparing the data obtained from the accelerometer with the sleep status data obtained by a previously validated sleep monitoring system. The Random Forest model was able to classify sleep and wakefulness with a 97.4% and 85.4% precision, respectively, which were comparable to those of conventional acceleration-based sleep monitoring devices. Additionally, the same data acquisition method was used to classify exercise intensity into seven levels and a high correlation (r=0.813, p<0.0001) was found when comparing the classified exercise intensity to metabolic equivalent (MET) values. This suggests that the proposed method can be used for accurate measurement of both behavioral sleep and physical activity classifying over a long period of time.

physiology↗

bioRxiv2023

Structural alterations in the amygdala and impaired social incentive learning in a mouse model of a genetic variant associated with neurodevelopmental disorders

Copy number variants (CNVs) are robustly associated with psychiatric disorders and their dimensions and changes in brain structures and behavior. However, as CNVs contain many genes, the precise gene-phenotype relationship remains unclear. Although various volumetric alterations in the brains of 22q11.2 CNV carriers have been identified in humans and mouse models, it is unknown how the genes in the 22q11.2 region individually contribute to structural alterations and associated mental illnesses and their dimensions. Our previous studies have identified Tbx1, a T-box family transcription factor encoded in 22q11.2 CNV, as a driver gene for social interaction and communication, spatial and working memory, and cognitive flexibility. However, it remains unclear how TBX1 impacts the volumes of various brain regions and their functionally linked behavioral dimensions. In this study, we used volumetric magnetic resonance imaging analysis to comprehensively evaluate brain region volumes in congenic Tbx1 heterozygous mice. Our data show that the volumes of anterior and posterior portions of the amygdaloid complex and its surrounding cortical regions were reduced in Tbx1 heterozygous mice. Moreover, we examined the behavioral consequences of an altered volume of the amygdala. Tbx1 heterozygous mice were impaired for their ability to detect the incentive value of a social partner in a task that depends on the amygdala. Our findings identify the structural basis for a specific social dimension associated with loss-of-function variants of TBX1 and 22q11.2 CNV.

neuroscience↗

bioRxiv2023

Cyclical control of female rejection behavior by progesterone receptor expressing neurons of the anterior ventromedial hypothalamus

Internal state-dependent behavioral responses, such as the switch between rejection and acceptance of sexual advances depending on a females reproductive capacity, are fundamental to maintain social interactions and wellbeing. Here we characterize a dedicated circuit for the cyclical control of rejection behavior in the mouse, located in the anterior ventrolateral ventromedial hypothalamus (aVMHvl). In vivo recordings reveal that progesterone receptor expressing neurons of the aVMHvl (aVMHvlPr+) are active during rejection but silent when females accept the male. Moreover, we show that aVMHvlPr+ neurons receive reduced excitatory to inhibitory synaptic input balance during the receptive phase of the reproductive cycle. Finally, optogenetic activation of aVMHvlPr+ neurons in receptive females is sufficient to increase rejection behavior, disrupting the probability of copulation, without affecting other male-directed interactions. This population of aVMHvlPr+ neurons is thus a key neural substrate controlling female sexual behavior, providing an additional barrier to mating when fertilization is not possible.

neuroscience↗

bioRxiv2022

The Administration Effect of Lactic Acid Bacteria Reducing Environmental Alkyl and Fatty Acid Hydroperoxides on Piglets in the Absence of Antimicrobial Agents and in the Presence of Iron

A lactic acid bacterium, Lactiplantibacillus plantarum P1-2 (LpP1-2), can reduce environmental fatty acid hydroperoxides. The administration of LpP1-2 to oxygen-sensitive short-lived nematode mutants and iron-overloaded rats reduced the oxidative stress-related index. Since young piglets have a weak defense system against oxidative stress and are vulnerable to environmental stress, antimicrobial agents have been administered in the rearing. Based on these results, we investigated the effect of LpP1-2 administration to prepartum sows and infant piglets until weaning without antimicrobial agents on the growth of young piglets. The group including both sows and piglets that were administrated with lactic acid bacteria containing LpP1-2 (LABLp) until the end of lactation showed the growth-promoting effect of piglet from lactation to early regular rearing, and even in late regular rearing. Blood biochemical markers were in the normal ranges in both LABLp-administrated and non-administrated groups, but various disease-related markers tended to decrease in the administrated group. To investigate the effects of LABLp administration on postpartum piglets, the piglets born from prenatally LABLp-administrated sows were divided into two groups and then administrated with or without LABLp. The piglets in the LABLp-administrated group tended to grow very slightly higher than those in the non-administrated group from lactation to early regular rearing. After that, the growth in both groups was almost the same. These results suggest that LABLp administration to prepartum sows is essential for the growth-promoting effect. The postnatal LABLp-administrated piglets showed a lower serum lipid peroxidation index than the non-administrated piglets, and had higher numbers of lactic acid bacteria and bifidobacteria in feces at the end of LABLp treatment. In fattening performances, the LABLp-administrated group showed a significant improvement in meat quality. We also discuss the growth and physiological effects by LpP1-2 administration with iron on piglets because iron administration is another important issue in piglet farming.

microbiology↗

bioRxiv2022

The oxytocin system regulates tearing

Tears are an exocrine physiological fluid secreted onto the ocular surface from the lacrimal apparatus in all mammals. Limited research has been conducted on the functional neuronal circuitry of tear production. In particular, the neuronal mechanisms of emotional tearing, which is a physiological reaction harmonized with enhanced emotional arousal and assumed to be unique to humans, remain unclear. We identified that the oxytocin neurons in the paraventricular hypothalamus is functionally projected to the oxytocin receptor-expressing neurons in the lacrimation center of the superior salivatory nucleus. Optogenetic activation or inhibition of these neurons and/or receptors can modulate the superior salivatory nucleus dependent tear secretion mediated through oxytocin. Moreover, we identified that maternal behavior, nociceptive behavior stimulation, and aversive memory retrieval are linked to tearing in mice, and that these emotional linked tearing are suppressed by optogenetic inhibition of the corresponding oxytocin system. Thus, tearing could be regulated through functional connections between central oxytocin systems in the paraventricular hypothalamus and the superior salivatory nucleus.

animal behavior and cognition↗

bioRxiv2021

Humanized substitutions of Vmat1 in mice induce changes in amygdala-dependent behaviors associated with the evolution of anxiety in humans

The human vesicular monoamine transporter 1 (VMAT1) harbors unique substitutions (Asn136Thr/Ile) that affect monoamine uptake into synaptic vesicles. These substitutions are absent in all known mammals, suggesting their contributions to distinct aspects of human behavior modulated by monoaminergic transmission, such as emotion and cognition. To directly test the impact of these human-specific mutations, we introduced the humanized residues into mouse Vmat1 via CRISPR/Cas9-mediated genome editing and examined changes at the behavioral, neurophysiological and molecular levels. Behavioral tests revealed reduced anxiety-related traits of Vmat1Ile mice, consistent with human studies, and electrophysiological recordings showed altered oscillatory activity in the amygdala under anxiogenic conditions. Transcriptome analyses further identified amygdala-specific changes in the expression of genes involved in neurodevelopment and emotional regulation, which may corroborate the observed phenotypes. This knock-in mouse model hence provides compelling evidence that the mutations affecting monoaminergic signaling and amygdala circuits have contributed to the evolution of human socio-emotional behaviors.

evolutionary biology↗

bioRxiv2019

Sexual imprinting overrides order effects

Mate choice is a complex decision that requires the integration of cues from potential mates with individual preferences. Choosers preferences are shaped by recent events, early life experience and by the evolutionary history of its own species. To better understand the interaction between these factors, we studied mate choice in the female house mouse, Mus musculus. Females of one of the musculus subspecies, Mus musculus musculus, show preference for males of their own subspecies compared to males of the sibling subspecies, Mus musculus domesticus. Such an assortative preference is ecologically relevant at contact zones, where it contributes to the reproductive isolation of sympatric populations and can be reproduced in controlled laboratory conditions, but its origins are still under debate. Here, we show that female mouse mate choice depends on both early postnatal life experience and the order of prospective mates encountered as an adult and that these effects interact asymmetrically. Whereas females raised in their normal M. m. musculus environment display a robust assortative preference, females fostered in a M. m. domesticus family prefer the first male encountered, regardless of subspecies. Thus, early life experience of M. m. musculus females, when concordant with genetic self-identity, overrides sampling order effects, ensuring robust assortative choice. In the absence of this match between phylogeny and early life experience, first impression effects dominate mate choice.

animal behavior and cognition↗

bioRxiv2018

Differential encoding of predator fear in the ventromedial hypothalamus and periaqueductal grey

The ventromedial hypothalamus is a central node of the mammalian predator defense network. Stimulation of this structure in rodents and primates elicits abrupt defensive responses, including flight, freezing, sympathetic activation, and panic, while inhibition reduces defensive responses to predators. The major efferent target of the ventromedial hypothalamus is the dorsal periaqueductal grey, and stimulation of this structure also elicits flight, freezing, and sympathetic activation. However, reversible inhibition experiments suggest that the ventromedial hypothalamus and periaqueductal grey play distinct roles in the control of defensive behavior, with the former proposed to encode an internal state necessary for the motivation of defensive responses, while the latter serves as a motor pattern initiator. Here we used electrophysiological recordings of single units in behaving mice exposed to a rat to investigate the encoding of predator fear in the dorsomedial division of the ventromedial hypothalamus and the dorsal periaqueductal grey. Distinct correlates of threat intensity and motor responses were found in both structures, suggesting a distributed encoding of sensory and motor features in the medial hypothalamic-brainstem instinctive network.

neuroscience↗