TABLE 2.

Comparison of in vitro patient derived cell culture models: practical aspects related to culturing procedures (non neural cell cultures e.g. fibroblasts/blood cells, iPSCs derived 2D neural cell cultures, ²² iPSCs derived 3D neural cell cultures, ²² direct reprogrammed neural cell cultures, ^{23 , 24} resected human brain tissue cultures. ^{25 , 26 , 27 , 28}

Patient‐derived cell cultures	Non neural cell cultures (fibroblasts/blood cells)	IPSCs derived 2D neural cell cultures	IPSCs derived 3D neural cell cultures	Direct reprogrammed neural cell cultures	Resected human brain tissue cultures
Basic characteristic	Represents pathophysiology of general cellular processes, and metabolism, suitable for genetic screening	Represents a broad range of neural cell types, providing a platform for disease modeling (synapses, electrical activity, neural proteins, neural networks, cell–cell interactions)	Models in vivo like conditions, allows complex interactions, stuctural changes, cell type composition, neurogenesis, cell migration, neural connectivity, electrical activity	Direct conversion to neural cells without going through the pluripotent state (synapses, electrical activity, neural proteins, basic properties of neural network, cell–cell interactions)	Reflects in vivo conditions, preserves cytoarchitecture, cell type composition, neural connectivity, electrical activity of epileptogenic neural tissue, suitable for genetic screening
Primary cells or tissue sample	Non neural cells	Non neural cells	Non neural cells	Non neural cells	Brain tissue
Presence of brain specific de novo somatic variants	Limited (depends on primary cells)	Limited (depends on primary cells)	Limited (depends on primary cells)	Limited (depends on primary cells)	Yes (brainarea dependent)
Invasiveness of cell or tissue collection	Non invasive (potentially invasive for obtaining skin fibroblasts)	Non invasive (potentially invasive for obtaining skin fibroblasts)	Non invasive (potentially invasive for obtaining skin fibroblasts)	Non invasive (potentially invasive for obtaining skin fibroblasts)	Invasive (brain surgery)
Developmental stage	Patient's age	Early stages of development	Early stages of development	Patient's age	Patient's age
Demands for cell system establishment
Procedure	Easy	Challenging (requires iPSC generation from non neural cells and 2D neural differentiation)	Challenging (requires iPSC generation from non neural cells and 3D neural differentation)	Moderate	Challenging (requires surgical resection of brain tissue; from a specific subgroup of patients)
Time	Short (days–months)	Long (usually shorter than 3D cultures; 1–3 years) Ref. [22]	Long (1–3 years) Ref. [22]	Moderate (1–5 months) Refs. [23, 24]	Short (days–months) Refs. [25, 26, 27, 28]
Financial cost	Low	High (influenced by reprogramming and differentiation procedures)	High (influenced by reprogramming and longer differentiation procedures)	Moderate (influenced by direct reprogramming procedures)	Low (excluding the financial cost of the surgery)

Abbreviations: 2D, two dimensional; 3D, three dimensional; iPSCs, induced pluripotent stem cells.