Related Experiment Video
Updated: Jul 14, 2026
Ex utero Electroporation and Whole Hemisphere Explants: A Simple Experimental Method for Studies of Early Cortical Development
Published on: April 3, 2013
Transient patterns of cortical lamination during prenatal life: do they have implications for treatment?
1Section for Developmental Neuroscience, Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000 Zagreb, Croatia. ikostov@hiim.hr
Insights
Transient neuronal circuitry in the developing brain forms temporary connections and functions. This transient circuitry is crucial for brain plasticity and moderating injury effects during early life.
Area of Science:
- Neuroscience
- Developmental Biology
- Neuroanatomy
Background:
- Transient laminae with circuitry elements emerge in the cerebral wall around 8 postconceptional weeks (PCW).
- The subplate zone, containing diverse neurons and synapses, is prominent during fetal development and marks regional boundaries.
- Thalamocortical afferents accumulate in the subplate zone during late fetal development.
Purpose of the Study:
- To describe the emergence, development, and disappearance of transient neuronal circuitry in the developing brain.
- To elucidate the role of transient circuitry in cortical development and plasticity.
- To understand how this circuitry influences the brain's response to injury.
Main Methods:
- Histological and anatomical analysis of developing brain tissue.
- Tracing of neuronal pathways, including thalamocortical and corticocortical projections.
- Observation of synaptic development and neuronal cell types during fetal and early postnatal periods.
Main Results:
- Transient laminae with synapses, neurons, and axons appear early and resolve after 6 months postnatally.
- The subplate zone contains GABAergic, glutamatergic, and peptidergic neurons and serves as a temporary relay for thalamocortical fibers.
- In preterm infants, thalamocortical fibers begin to establish connections within the cortical plate, while corticocortical pathways mature.
Conclusions:
- Transient neuronal circuitry supports temporary functions in fetal and early postnatal life.
- This transient circuitry is fundamental to the developmental plasticity of the cerebral cortex.
- It plays a role in moderating the effects of brain lesions during development.
Abstract:
Transient laminae containing circuitry elements (synapses, postsynaptic neurons and presynaptic axons) appear in the cerebral wall from the eighth postconceptional week (PCW) and disappear with the resolution of the subplate zone after the sixth postnatal month. The first endogeneous synaptic circuitry develops in two laminae, above and below the cortical plate. Mid- and late fetal period (15-23PCW) shows lamination pattern with a thick subplate zone containing GABAergic, glutamatergic and peptidergic neurons, synapses and thalamocortical afferents which are waiting and accumulating in the superficial subplate zone between 21 and 23PCW and these mark regional boundaries. In preterm infants, some thalamocortical fibers relocate to the cortical plate in visual, somatosensory, auditory and associative cortices, forming a framework for sensory-driven connectivity, while other remain engaged in the endogeneous subplate zone circuitry. Corticocortical pathways continue to grow. In the neonatal period, there is a major reorganization of callosal projections and development of short corticocortical connections, dendritic spines and synapses. In conclusion, transient neuronal circuitry underlies transient functions during the fetal, perinatal and early postnatal life and determines developmental plasticity of the cerebral cortex and moderates effects of lesion of the developing brain.
