Biology subjects

Aoyama, B. B.

Publications and source records attributed to Aoyama, B. B..

3 recordsLinked to original sources

bioRxiv2025

Mu opioid receptor mRNA and protein localization across the rat and mouse habenula

The habenula (Hb) has high intensity mu opioid binding and receptor (MOR) expression. It contains medial and lateral subdivisions (MHb and LHb, respectively), yet the details of MOR localization across these regions remains debated. MHb and LHb participate in largely non-overlapping neural circuits, therefore accurately resolving MOR expression across them is critical for understanding how MOR ligands impact behaviors. Here we utilized in situ hybridization (ISH) and immunocytochemistry (ICC) to systematically map Oprm1 mRNA and MOR protein throughout the habenular complex. We studied rat and mouse tissue to evaluate expression across two common research species. We also performed parallel mapping in Oprm1-Venus/Venus mice. Importantly, we found mRNA and protein in both MHb and LHb in both species. In rat, 39 {+/-} 3% and 21 {+/-} 4% of cells expressed Oprm1 in MHb and LHb, respectively. These proportions were greater in mouse: 57 {+/-} 1% (MHb) and 32 {+/-} 4% (LHb). Oprm1 puncta per positive cell were greater in MHb compared to LHb for both rat and mouse (p < 0.0001). The highest intensity labeling was localized along the lateral edge of the MHb for all methods. ICC showed MOR localized to fibers and somata in both regions. In LHb, MOR labeling was most dense in intermediate sections along the anterior-posterior (AP) axis. In rats we also observed greater labeling in dorsal LHb at intermediate AP levels and medial LHb more posteriorly. These results indicate that both MHb and LHb can contribute to MOR mediated actions through their respective circuits. Key PointsO_LIMu opioid receptor mRNA and protein are expressed in both the medial and lateral habenulae in rat and mouse. C_LIO_LIIn the medial habenula, most mu opioid receptor mRNA and protein was detected along its lateral border. C_LIO_LIAcross samples, Oprm1+ cells in the MHb contained more mRNA puncta per cell compared to lateral habenula cells. C_LI

neuroscience↗

bioRxiv2025

Transcriptomic analysis of perirhinal and lateral entorhinal Cortex sub-regions in male mice

The perirhinal cortex (PER) is crucial for object recognition memory and comprises areas 35 and 36. The lateral entorhinal cortex (LEC), subdivided into dorsolateral (DLE) and ventral intermediate (VIE) regions, plays a key role in encoding representations of objects, events, contextual details, and sequential information. Despite their anatomical distinctions, gene expression profiling of these subregions remains limited. To address this gap, we conducted transcriptome analysis of these regions in C57BL/6 mice. Tissue samples were collected using laser microdissection, isolating PER areas 35 and 36, as well as DLE and VIE subregions of the LEC, and subsequently analyzed via RNA sequencing. Our results revealed no significant gene expression differences between PER areas 35 and 36, yet substantial molecular divergence emerged when comparing PER to LEC subregions. The PER exhibited higher expression of genes related to nutritional state sensitivity compared to the LEC, while the DLE showed elevated expression of genes implicated in axonal guidance, neurotrophic support, and glutamatergic neurotransmission relative to the VIE. These findings advance our understanding of the molecular profiles unique to PER and LEC regions, and may support the generation of novel hypotheses regarding functional roles of these cortical populations that may be explored in future research.

molecular biology↗

bioRxiv2021

Transcriptomic analysis of dorsal and ventral subiculum after induction of acute seizures by electric stimulation of the perforant pathway in rats

Preconditioning is a mechanism in which injuries induced by non-lethal hypoxia or seizures trigger cellular resistance to subsequent events. Norwood et al., in a 2010 study, showed that an 8-hour-long period of electrical stimulation of the perforant pathway in rats is required for the induction of hippocampal sclerosis. However, in order to avoid generalized seizures, status epilepticus (SE), and death, a state of resistance to seizures must be induced in the hippocampus by a preconditioning paradigm consisting of 2 daily 30-minute stimulation periods. Due to the importance of the subiculum in the hippocampal formation, this study aims to investigate differential gene expression patterns in the dorsal and ventral subiculum using RNA-sequencing, after induction of a preconditioning protocol by electrical stimulation of the perforant pathway. The dorsal (dSub) and ventral (vSub) subiculum regions were collected by laser-microdissection 24 hours after preconditioning protocol induction in rats. RNA sequencing was performed in a Hiseq 4000 platform, reads were aligned using the STAR and DESEq2 statistics package was used to estimate gene expression. We identified 1176 differentially expressed genes comparing control to preconditioned subiculum regions, 204 genes were differentially expressed in dSub and 972 in vSub. The gene ontology enrichment analysis showed that the most significant common enrichment pathway considering up-regulated genes in dSub and vSub was Cholesterol Biosynthesis. In contrast, the most significant enrichment pathway considering down-regulated genes in vSub was Axon guidance. Our results indicate that preconditioning induces synaptic reorganization, increased cholesterol metabolism, and astrogliosis in both dSub and vSub. Both regions also presented a decrease in glutamatergic transmission, an increase in complement system activation, and increased in GABAergic transmission. The down-regulation of proapoptotic and axon guidance genes in the ventral subiculum suggests that preconditioning induces a neuroprotective environment in this region.

neuroscience↗