Role of axonal fibers in the cortical folding patterns: A tale of variability and regularity

Chavoshnejad, Poorya; Xiao, Li; Zhang, Songyao; Dai, Weiying; Vasung, Lana; Liu, Tianming; Zhang, Tuo; Wang, Xianqiao; Razavi, Mir Jalil

doi:10.1016/j.brain.2021.100029

Cited by 23 publications

(26 citation statements)

References 125 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This wiring principle leads to modular and clustered network structures in which neurons and regions performing functionally related tasks are typically adjacent to decrease the wiring costs ( Bassett and Bullmore, 2006 ; Wang and Clandinin, 2016 ; Casanova and Casanova, 2019 ). Examples of structural clustering are cortical folding and gyrification in order to bring structurally separated regions together ( Wang and Clandinin, 2016 ; Chavoshnejad et al, 2021 ). Separation of gray and white matter in vertebrates is another example of how local circuits or modules are clustered but connected through long-range axons ( Wang and Clandinin, 2016 ; Richards and Van Hooser, 2018 ; Martinez and Sprecher, 2020 ).…”

Section: Discussionmentioning

confidence: 99%

Long-term morphological and functional dynamics of human stem cell-derived neuronal networks on high-density micro-electrode arrays

et al. 2022

View full text Add to dashboard Cite

Comprehensive electrophysiological characterizations of human induced pluripotent stem cell (hiPSC)-derived neuronal networks are essential to determine to what extent these in vitro models recapitulate the functional features of in vivo neuronal circuits. High-density micro-electrode arrays (HD-MEAs) offer non-invasive recording with the best spatial and temporal resolution possible to date. For 3 months, we tracked the morphology and activity features of developing networks derived from a transgenic hiPSC line in which neurogenesis is inducible by neurogenic transcription factor overexpression. Our morphological data revealed large-scale structural changes from homogeneously distributed neurons in the first month to the formation of neuronal clusters over time. This led to a constant shift in position of neuronal cells and clusters on HD-MEAs and corresponding changes in spatial distribution of the network activity maps. Network activity appeared as scarce action potentials (APs), evolved as local bursts with longer duration and changed to network-wide synchronized bursts with higher frequencies but shorter duration over time, resembling the emerging burst features found in the developing human brain. Instantaneous firing rate data indicated that the fraction of fast spiking neurons (150–600 Hz) increases sharply after 63 days post induction (dpi). Inhibition of glutamatergic synapses erased burst features from network activity profiles and confirmed the presence of mature excitatory neurotransmission. The application of GABAergic receptor antagonists profoundly changed the bursting profile of the network at 120 dpi. This indicated a GABAergic switch from excitatory to inhibitory neurotransmission during circuit development and maturation. Our results suggested that an emerging GABAergic system at older culture ages is involved in regulating spontaneous network bursts. In conclusion, our data showed that long-term and continuous microscopy and electrophysiology readouts are crucial for a meaningful characterization of morphological and functional maturation in stem cell-derived human networks. Most importantly, assessing the level and duration of functional maturation is key to subject these human neuronal circuits on HD-MEAs for basic and biomedical applications.

show abstract

Section: Discussionmentioning

confidence: 99%

Long-term morphological and functional dynamics of human stem cell-derived neuronal networks on high-density micro-electrode arrays

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Initial perturbation in each model was applied as random and small displacements on the nodes of the cortex's surface. The amplitude of the displacements was 0.01 of the cortex thickness (Chavoshnejad et al 2021). Figure 8 shows the top views of 4 of the 30 models after suppressing the cortex layer.…”

Section: Resultsmentioning

confidence: 99%

Gyral peaks: Novel gyral landmarks in developing macaque brains

Zhang

Chavoshnejad

et al. 2022

Human Brain Mapping

Self Cite

View full text Add to dashboard Cite

Cerebral cortex development undergoes a variety of processes, which provide valuable information for the study of the developmental mechanism of cortical folding as well as its relationship to brain structural architectures and brain functions. Despite the variability in the anatomy-function relationship on the higher-order cortex, recent studies have succeeded in identifying typical cortical landmarks, such as sulcal pits, that bestow specific functional and cognitive patterns and remain invariant across subjects and ages with their invariance being related to a gene-mediated proto-map. Inspired by the success of these studies, we aim in this study at defining and identifying novel cortical landmarks, termed gyral peaks, which are the local highest foci on gyri. By analyzing data from 156 MRI scans of 32 macaque monkeys with the age spanned from 0 to 36 months, we identified 39 and 37 gyral peaks on the left and right hemispheres,

show abstract

“…This is of interest because this distribution is consistently observed in gyrencephalic species and is vital in distributing neurons within the cortex [ 13 ]. It has even been proposed that the orientation and distribution of radial glial fibers regulate cortical folding [ 13 , 14 ]. Our simulations show that the fan-like distribution of radial glial fibers arises naturally from the mechanical instabilities.…”

Section: Resultsmentioning

confidence: 99%

“…Neuronal connectivity and axon formation become increasingly active around P5, and the cortical organization becomes stable one month after birth [ 11 , 12 ]. The fan-like distribution of radial glial fibers induced by the buckling is consistently observed in gyrencephalic brains, which is essential for regulating neuronal migration and cortical folding [ 13 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

Orchestrated neuronal migration and cortical folding: A computational and experimental study

et al. 2022

View full text Add to dashboard Cite

Brain development involves precisely orchestrated genetic, biochemical, and mechanical events. At the cellular level, neuronal proliferation in the innermost zone of the brain followed by migration towards the outermost layer results in a rapid increase in brain surface area, outpacing the volumetric growth of the brain, and forming the highly folded cortex. This work aims to provide mechanistic insights into the process of brain development and cortical folding using a biomechanical model that couples cell division and migration with volumetric growth. Unlike phenomenological growth models, our model tracks the spatio-temporal development of cohorts of neurons born at different times, with each cohort modeled separately as an advection-diffusion process and the total cell density determining the extent of volume growth. We numerically implement our model in Abaqus/Standard (2020) by writing user-defined element (UEL) subroutines. For model calibration, we apply in utero electroporation (IUE) to ferret brains to visualize and track cohorts of neurons born at different stages of embryonic development. Our calibrated simulations of cortical folding align qualitatively with the ferret experiments. We have made our experimental data and finite-element implementation available online to offer other researchers a modeling platform for future study of neurological disorders associated with atypical neurodevelopment and cortical malformations.

show abstract

Role of axonal fibers in the cortical folding patterns: A tale of variability and regularity

Cited by 23 publications

References 125 publications

Long-term morphological and functional dynamics of human stem cell-derived neuronal networks on high-density micro-electrode arrays

Long-term morphological and functional dynamics of human stem cell-derived neuronal networks on high-density micro-electrode arrays

Gyral peaks: Novel gyral landmarks in developing macaque brains

Orchestrated neuronal migration and cortical folding: A computational and experimental study

Contact Info

Product

Resources

About