Biology subjects

Tobari, Y.

Publications and source records attributed to Tobari, Y..

3 recordsLinked to original sources

bioRxiv2025

Pleasure in groove is associated with neuromelanin levels in the substantia nigra of younger healthy individuals: A neuromelanin-sensitive MRI study

The pleasurable urge to move in response to music is called groove. Prior research has suggested a potential link between groove and dopamine function. However, no studies to date have directly investigated the relationship between the two. Here, we aimed to assess individual dopamine function in the substantia nigra of healthy individuals using neuromelanin-sensitive magnetic resonance imaging (NM-MRI), a non-invasive method associated with dopamine function, and to investigate the relationship between the individual dopamine proxy index and sensitivity to the groove experience. In this study, 15 younger (< 48 years) and 16 older ([greater double equals]48 years) healthy individuals participated. Participants listened to ten musical excerpts and rated the groove experience based on "pleasure" and "wanting to move." To assess whether the groove experience is related to NM levels, type of musical excerpts, and sex, we analyzed with linear mixed-effects regression models. The results showed that higher NM levels (p = 0.032) and male sex (p = 0.034) were associated with higher pleasure ratings in the younger group. For the "urge to move" ratings, type of musical excerpts was associated with ratings in both groups (ps < 0.001), where high-groove music (Janata et al., 2012) receiving higher ratings. Taken together, these results suggest that the "pleasure" aspect of the groove experience in younger individuals was related to dopamine levels in the substantia nigra, but may not be associated with the "urge to move." Thus, pleasure and the urge to move are likely to involve distinct dopaminergic pathways and mechanisms, warranting further investigation.

neuroscience↗

bioRxiv2021

Noradrenergic alpha-2A receptor activation suppresses courtship vocalization in male Japanese quail.

Male Japanese quail produce high-frequency crow vocalizations to attract females during the breeding season. The nucleus of intercollicularis (ICo) is the midbrain vocal center in birds and electrical stimulation of the ICo produces calls that include crowing. Noradrenaline plays a significant role in sexual behavior but the contribution of noradrenaline in the control of courtship vocalizations in quail has not been well established. Using dose-dependent intracerebroventricular injection of clonidine, an 2-adrenergic receptor- specific agonist, crowing vocalization was immediately suppressed. At the same time as crow suppression by clonidine there was a reduction of immediate early gene, zenk mRNA, in the ICo; no zenk mRNA expression was detected in the dorsomedial division of the nucleus. Using histochemistry, we determined that the ICo receives noradrenergic innervation and expresses 2A-adrenergic receptor mRNA. Taken together, these data suggest that noradrenaline regulates courtship vocalization in quail, possibly via the alpha2A- adrenergic receptor expressed on ICo neurons.

animal behavior and cognition↗

bioRxiv2021

Decreased synthesis and variable gene transcripts of oxytocin in a domesticated avian species

The Bengalese finch was domesticated more than 250 years ago from the wild white-rumped munia. Similar to other domesticated species, Bengalese finches show a reduced fear response and have lower corticosterone levels, compared to white-rumped munias. Bengalese finches and munias also have different song types. Since oxytocin (OT) has been found to be involved in stress coping and auditory processing, we tested whether the OT sequence and brain expression pattern and content differ in wild munias and domesticated Bengalese finches. We identified intra-strain variability in the untranslated regions of the OT sequence in Bengalese finches in comparison to the munia OT. Several of these changes fall in specific transcription factor binding sites, which show either a conserved or a relaxed evolutionary trend in the avian lineage, and in vertebrates in general. Although in situ hybridization in several hypothalamic nuclei did not reveal significant differences in the number of cells expressing OT between the two strains, real-time quantitative PCR showed significantly lower OT mRNA expression in the diencephalon of the Bengalese finches relative to munias. Our study thus points to a decreased OT synthesis in the domestic strain compared with the wild strain in birds. This is an opposite pattern from that found in some domesticated mammals, suggesting that different processes of OT function might have occurred in mammals and birds under domestication.

neuroscience↗