Three-dimensional (3D) neural culture systems, including organoids and spheroids, are increasingly recognized as powerful tools for modelling neurodegenerative diseases such as Alzheimer’s (AD) and Parkinson’s disease (PD). These models offer varying degrees of complexity, scalability, and physiological relevance. In this study we compare different approaches generating cerebral organoids and neural spheroids, highlighting their respective strengths and limitations in mimicking disease-specific pathophysiology.
Organoids, derived from pluripotent stem cells, are traditionally used for neurodevelopmental studies due to their structural complexity and ability to mimic early brain architecture. However, their application in neurodegeneration is limited by cellular immaturity and high variability. To address this limitation, we induced aging in cerebral organoids using D-galactose treatment, which led to reduced growth and strong upregulation of senescence markers such as p21. This approach enhances their relevance for age-related disease modelling, despite lower reproducibility and longer cultivation times.
Spheroids, in contrast, offer a more scalable and reproducible platform with shorter cultivation times. Within this category, we distinguish between neuronal precursor cells (NPCs)-derived spheroids and those formed by 3D aggregation of already differentiated iPSC-derived neurons. NPC-derived spheroids were used for AD modelling, where neural precursor cells from healthy and patient donors were differentiated into 3D structures.
The differentiated iPSC-derived spheroids were tailored to mimic specific brain regions: prefrontal cortex (PFC-like spheroids) for AD and ventral tegmental area (VTA-like spheroids) for PD. PFC-like spheroids responded to AD brain seeds with elevated GFAP and NF-L levels, while Aβ1-42 triggered stronger cytokine responses and neuronal activity changes. VTA-like spheroids, challenged with AAV-A53T α-synuclein and MPP⁺, revealed mild pathology under genetic insult but significant dopaminergic loss and mitochondrial dysfunction following chemical exposure.
In summary, organoids provide higher structural complexity and are valuable for studying neurodevelopmental processes and aging when senescence is induced. Spheroids, on the other hand, provide reproducibility and higher throughput, making them ideal for mechanistic studies and drug screening applications in neurodegenerative research. Together, these 3D models constitute a complementary toolkit for investigating disease mechanisms and evaluating therapeutic strategies.
