Medullary SpV-like Organoid Modeling Service

The medulla oblongata, a critical component of the hindbrain, orchestrates vital functions ranging from sensory processing to autonomic control. Within the medulla lies the spinal trigeminal nucleus (SpV), the primary relay center for processing sensory information, including pain and temperature, from the face and head to higher brain centers like the thalamus. Dysfunction in the SpV is implicated in debilitating neurological conditions, notably trigeminal neuralgia and other chronic pain states. However, studying this intricate nucleus and its human-specific aspects has been hampered by the lack of physiologically relevant in vitro models.

At Creative Biolabs, we bridge this gap with our cutting-edge Human Medullary SpV-like Organoid (hmSpVO) platform. Leveraging guided differentiation protocols for human pluripotent stem cells (hPSCs), we generate region-specific brain organoids that faithfully recapitulate key developmental and functional features of the human medullary SpV, providing an unprecedented window into its biology and pathology.

Our hmSpVO Platform: A High-Fidelity Model

Our hmSpVOs are meticulously characterized to ensure relevance and reliability for your research needs. They exhibit key hallmarks of the developing dorsal medulla, offering a robust system for investigating cellular interactions, circuit formation, and functional maturation.

Key Features:

• Authentic Cellular Diversity: hmSpVOs develop the characteristic neuronal subtypes found in the SpV, including distinct populations of excitatory (vGLUT2-positive) and inhibitory (GABAergic, PAX2-positive) neurons derived from appropriate progenitor domains (dBLa/dBLb-like).
• Structural Maturation: Over time in culture, hmSpVOs demonstrate significant structural organization. Neurons extend processes, and crucially, exhibit formation of coalesced axonal pathways, particularly near the organoid periphery, reminiscent of the developing spinal trigeminal tract in vivo. Mature astrocytes also emerge, contributing to a more complete neural environment.
• Functional Competence: hmSpVOs develop functional neural networks. They display spontaneous electrophysiological activity detectable by MEA, possess functional glutamatergic and GABAergic synapses confirmed by pharmacological modulation, and express synaptic markers like synaptophysin and PSD95. Furthermore, these organoids respond to physiologically relevant stimuli, such as the neuropeptide CGRP, known to modulate SpV activity in pain signaling.

Visualizing the intricate cellular landscape and maturation within our hmSpVOs provides direct evidence of their physiological relevance. Immunostaining confirms the presence and organization of key SpV neuronal populations, including LMX1B+ excitatory neurons and PAX2+ inhibitory neurons, alongside developing astrocytes (GFAP+/S100ß+) in long-term cultures, demonstrating progressive maturation towards a complex neural tissue.

Fig.1 Generation and characterization of hmSpVOs from hPSCs.^1,2

Modeling Neural Circuits: The Human SpV-Thalamus Assembloid (hSTO)

Understanding how the SpV integrates into larger sensory circuits is crucial. Our platform extends to modeling the critical connection between the SpV and the thalamus – the trigeminothalamic pathway. By fusing our hmSpVOs with human thalamic organoids (hThOs ) in an optimized air-liquid interface culture, we create human SpV-Thalamus Organoids (hSTOs).

hSTO Capabilities:

• Recapitulating Connectivity: hSTOs robustly form directed axonal projections from the hmSpVO component into the hThO component, effectively modeling the anatomical basis of the trigeminothalamic tract. Intriguingly, this projection shows a bias, mirroring the predominantly unidirectional nature of this pathway in vivo.
• Demonstrating Functional Links: We utilize advanced techniques like retrograde viral tracing, optogenetics, and high-density MEA recordings to confirm that these anatomical projections establish functional synaptic connections between SpV-like and thalamic-like neurons within the hSTO.

Our hSTO assembloids provide compelling visual and functional evidence of trigeminothalamic circuit formation in vitro. Live imaging reveals extensive axonal outgrowth from the hmSpVO specifically targeting and innervating the hThO (labeled, e.g., GFP). Histological analysis shows these projections forming distinct tracts, and retrograde tracing confirms their origin from SpV neurons. These structural connections are functionally validated through techniques like optogenetics, demonstrating signal transmission from SpV to thalamic neurons.

Fig.2 Fusing hmSpVOs and hThOs successfully replicates key aspects of the trigeminothalamic tract.^1,3

Comprehensive Service Offerings

Leverage our expertise and validated hmSpVO/hSTO platforms to accelerate your research:

• Model Generation: Reliable production of hmSpVOs, hSTOs, and relevant control organoids using standard or client-specific cell lines.
• Advanced Functional Analysis: Electrophysiological profiling (MEA), calcium imaging, optogenetic interrogation, and pharmacological/neuropeptide response testing.
• Circuit Mapping: Detailed analysis of axonal projection patterns and connectivity in hSTO assembloids using state-of-the-art tracing and functional methods.
• Disease Modeling & Screening: Custom assay development for studying SpV-related pathologies and screening compounds for therapeutic potential or neurotoxicity.

Applications

Our hmSpVO and hSTO models provide powerful tools for:

• Investigating fundamental mechanisms of human hindbrain development and SpV specification.
• Modeling trigeminothalamic circuit formation and function.
• Studying the cellular and circuit basis of orofacial sensory processing, nociception, and pain.
• Developing models for trigeminal neuralgia and related neuropathic pain conditions.
• Screening and validating novel therapeutic agents targeting sensory or pain pathways.

Our Workflow

Partner with the Experts

At Creative Biolabs, we combine deep neurobiological expertise with robust, reproducible organoid technology. We offer tailored project design, rigorous quality control, and comprehensive data analysis to deliver actionable insights for your discovery programs.

Ready to explore the potential of human medullary SpV models for your research?

Contact Creative Biolabs!

References

1. Pang, Wei et al. “Generation of human region-specific brain organoids with medullary spinal trigeminal nuclei.” Cell stem cell vol. 31,10 (2024): 1501-1512.e8. doi:10.1016/j.stem.2024.08.004.
2. Distributed under Open Access License CC BY 4.0. The original image was modified.
3. Distributed under Open Access License CC BY 4.0 without modification.