Search bioRxiv⌕ Search

Biology subjects

Matsushima, S.

Publications and source records attributed to Matsushima, S..

3 recordsLinked to original sources

Systemic injection of metabotropic glutamate 2/3 receptor antagonist LY341495 disrupts reward-related behaviors in mice.

Metabotropic glutamate 2/3 receptors (mGluR2/3) have been implicated in depression, anxiety, learning, and memory, yet their role in reward-related behavior remains poorly understood. Here, we examined the effects of the selective mGluR2/3 antagonist LY341495 on reward-related behaviors in mice using a combination of head-fixed and freely moving behavioral paradigms. In a head-fixed temporal conditioning task, mice developed anticipatory licking and pupil dilation preceding the delivery of a 10% sucrose solution, indicating successful temporal anticipation of reward. Systemic administration of LY341495 dose-dependently reduced both anticipatory and consummatory licking. Normalization analyses further suggested that LY341495 reduced the overall expression of licking behavior while largely preserving its temporal organization. LY341495 also induced pupil dilation and attenuated reward-proximity-related pupillary modulation. To determine whether these effects reflected non-specific motor impairments, we assessed locomotor activity in an open-field task and measured ultrasonic vocalizations (USVs) during courtship interaction. LY341495 did not significantly alter locomotion, excretion, or USV production, suggesting preserved general motor and orofacial motor function. In contrast, LY341495 dose-dependently reduced food intake and decreased social preference, indicating that the effects of mGluR2/3 antagonism extend beyond ingestive behavior to social reward-related processes. These findings demonstrate that mGluR2/3 signaling contributes to the regulation of reward-related behaviors across multiple reward domains independently of general motor dysfunction. These results provide new insight into glutamatergic mechanisms underlying motivation and reward processing and may have implications for neuropsychiatric disorders characterized by anhedonia and motivational deficits.

neuroscience↗

Disruption of ultrasonic vocalization with systemic administration of the non-competitive N-methyl-d-aspartate receptor antagonist MK-801 in adult male mice

Objective: Social behavior and communication, including ultrasonic vocalizations (USVs), are important for survival and reproductive success across species. N-methyl-D-aspartate (NMDA) receptors contribute to the neural mechanisms underlying social behavior, and pharmacological modulation of these receptors can alter both social behavior and USVs in rodents. However, the effects of NMDA receptor blockade on dyadic USVs and social approach during male-female interactions in mice remain incompletely understood. We therefore investigated the effects of systemic administration of MK-801, a noncompetitive NMDA receptor antagonist, on dyadic vocal activity, social approach, locomotor behavior, and excretory outcomes in adult male mice. Methods: Sexually experienced male mice were tested in male-female interaction and same-sex social-preference tasks. Using VocalMat, a machine-learning-based tool, we classified the USVs recorded during male-female interactions into 11 call categories and examined their temporal relationship to the proximity of the male subject to the female stimulus. Results: Administration of MK-801 to the male dose-dependently reduced the total number of USVs recorded from the male-female dyad, with a marked reduction at the highest dose, while leaving the treated male's proximity to the female stimulus unchanged. In the same-sex social-preference task, MK-801 reduced the time spent near the social stimulus at the highest dose, although preference for the social stimulus over the non-social object remained significant under all treatment conditions. MK-801 also increased locomotor activity and reduced fecal output and estimated urine output in the open-field task. These findings demonstrate that systemic NMDA receptor blockade differentially affects dyadic vocal communication, social approach, locomotor activity, and excretory outcomes. Conclusion: Systemic MK-801 administration to the male reduced the number of USVs recorded during male-female interactions and produced distinct effects on social approach, locomotor activity, and excretory outcomes. These findings indicate that NMDA receptor blockade differentially affects multiple behavioral domains, although the mechanisms underlying the reduction in USVs remain to be determined.

pharmacology and toxicology↗

mitoNEET Regulates Mitochondrial Iron Homeostasis Interacting with Transferrin Receptor

Iron is an essential trace element for regulation of redox and mitochondrial function, and then mitochondrial iron content is tightly regulated in mammals. We focused on a novel protein localized at the outer mitochondrial membrane. Immunoelectron microscopy revealed transferrin receptor (TfR) displayed an intimate relationship with the mitochondria, and mass spectrometry analysis also revealed mitoNEET interacted with TfR in vitro. Moreover, mitoNEET was endogenously coprecipitated with TfR in the heart, which indicates that mitoNEET also interacts with TfR in vivo. We generated mice with cardiac-specific deletion of mitoNEET (mitoNEET-knockout). Iron contents in isolated mitochondria were significantly increased in mitoNEET-knockout mice compared to control mice. Mitochondrial reactive oxygen species (ROS) were higher, and mitochondrial maximal capacity and reserve capacity were significantly decreased in mitoNEET-knockout mice, which was consistent with cardiac dysfunction evaluated by echocardiography. The complex formation of mitoNEET with TfR may regulate mitochondrial iron contents via an influx of iron. A disruption of mitoNEET could thus be involved in mitochondrial ROS production by iron overload in the heart.

cell biology↗