Biology subjects

Narikiyo, K.

Publications and source records attributed to Narikiyo, K..

4 recordsLinked to original sources

bioRxiv2026

Sustained effect of MPOA Penk neurons underlies progression through consummatory mating behavior in male mice

Male rodent sexual behavior progresses from appetitive to consummatory mating, implying a sustained internal motivational state. Estrogen receptor 1 (Esr1)-expressing neurons in the medial preoptic area (MPOA) regulate discrete mating actions, but how motivational drive is sustained across mating remains unknown. Here, we identify an MPOA Esr1+ neuronal subtype marked by proenkephalin (Penk) that promotes the transition from mount to intromission. Male mice exhibited a bimodal progression to consummatory mating, and Penk-expressing neurons represented the predominant population recruited for consummatory behaviors. In sexually active males, Penk+ neurons exhibited sustained Ca{superscript 2} dynamics. Chemogenetic manipulation selectively enhanced female-directed consummatory behaviors without affecting intermale interactions. Optogenetic activation of Penk+ neurons or their terminals promoted consummatory behavior over a behaviorally relevant timescale. Thus, MPOA Penk+ neurons provide a circuit substrate for a sustained internal state that ensures successful mating progression.

neuroscience↗

bioRxiv2025

Maternal care during early development is necessary for the acquisition of a calming response to back stroking

In many mammals, early postnatal interactions between caregivers and offspring involve rich physical contact, including stroking, holding, and grooming. Offspring typically remain calm and close to the caregiver during such stimulation. Although these behaviors are thought to support emotional regulation and bonding during infancy, the underlying mechanisms and the role of prior experience remain unclear. Here, we demonstrate that back stroking induces a conserved calming response in both human infants and mouse pups, characterized by reduced movement and heart rate. In mouse pups, stroking further facilitated sleep onset, increased EEG delta power, and attenuated stress-induced corticosterone elevations. These sleep-promoting and stress-buffering effects were absent in artificially reared pups deprived of postnatal maternal contact, underscoring the importance of early tactile experience. Transcriptomic analysis revealed downregulation of the voltage-gated calcium channel subunit gene Cacna1b in the hypothalamus of artificially reared pups. Moreover, knockdown of hypothalamic Cacna1b in maternally reared pups abolished stroking-induced calming and sleep-promoting effects. This study identifies a conserved, experience-dependent calming response to affiliative tactile input, biologically embedded through plasticity, that supports physiological regulation and stress resilience during early development. Our results highlight that affiliative tactile sensation, like discriminative tactile sensation, depends on early experience to organize neural mechanisms regulating internal states. SignificanceEarly-life physical contact with caregivers is essential for healthy emotional and physiological development in mammals, but its underlying mechanisms remain unclear. We show that back stroking induces a conserved calming response in both human infants and mouse pups, reducing movement, heart rate, and promoting sleep. These effects depend on early tactile experience and are mediated by Cacna1b expression in the hypothalamus. Our findings identify a plastic, experience-dependent pathway through which affiliative tactile input modulates internal states, revealing how parental care supports stress resilience and sleep physiology during early development.

neuroscience↗

bioRxiv2018

Respiration-phased switching between sensory inputs and top-down inputs in the olfactory cortex

Olfactory perception depends on respiration phases: olfactory cortex processes external odor signals during inhalation whereas it is isolated from the external odor world during exhalation. Olfactory cortex pyramidal cells receive the sensory signals via bottom-up pathways terminating on superficial layer (SL) dendrites while they receive top-down inputs on deep layer (DL) dendrites. Here we asked whether olfactory cortex pyramidal cells spontaneously change the action modes of receiving olfactory sensory inputs and receiving top-down inputs in relation to respiration phases. Current source density analysis of local field potentials recorded in three different olfactory cortex areas of waking immobile rats revealed {beta}- and {gamma}-range fast oscillatory current sinks and a slow current sink in the SL during inhalation, whereas it showed {beta}- and {gamma}-range fast oscillatory current sinks and a slow current sink in the DL during exhalation. Sensory deprivation experiments showed that inhalation-phased olfactory sensory inputs drove the inhalation-phased fast oscillatory potentials in the SL but they drove neither the inhalation-phased slow current sink in the SL nor the exhalation-phased slow current sink in the DL. The results indicate that independent of inhalation-phased olfactory sensory inputs, olfactory cortex pyramidal cells spontaneously generate a slow depolarization in the SL dendrites during inhalation, which may selectively boost the concomitant olfactory sensory inputs to elicit spike outputs. In addition, the pyramidal cells spontaneously generate slow depolarization in the DL dendrites during exhalation, which may assist top-down inputs to elicit spike outputs. We thus hypothesize that the olfactory cortical areas coordinately perform inhalation/exhalation-phased switching of input biasing: inhalation phase is the time window for external odor signals that arrive in the SL dendrites, whereas exhalation phase is assigned to boost top-down signals to the DL dendrites that originate in higher brain centers.

neuroscience↗

bioRxiv2018

The Claustrum Coordinates Cortical Slow-Wave Activity

During sleep and awake rest, the neocortex generates large-scale slow-wave activity. Here we report that the claustrum, a poorly understood subcortical neural structure, coordinates neocortical slow-wave generation. We established a transgenic mouse line allowing genetic and electrophysiological interrogation of a subpopulation of claustral glutamatergic neurons. These claustral excitatory neurons received inputs from glutamatergic neurons in a large neocortical network. Optogenetic activation of claustral neurons in vitro induced excitatory post-synaptic responses in most neocortical neurons, but elicited action potentials primarily in inhibitory interneurons. Optogenetic activation of claustral neurons in vivo induced a Down-state featuring a prolonged silencing of neural acticity in all layers of many cortical areas, followed by a globally synchronized Down-to-Up state transition. These results demonstrate a crucial role of the claustrum in synchronizing inhibitory interneurons across the neocortex for spatiotemporal coordination of brain state. Thus, the claustrum is a major subcortical hub for the synchronization of neocortical slow-wave activity.

neuroscience↗