Related Experiment Videos
Prenatal development of GABA-ergic neurons in the neocortex of the rat
C G Van Eden1, L Mrzljak, P Voorn
1Netherlands Institute for Brain Research, Amsterdam.
Insights
GABA-ergic neurons are present throughout the prenatal rat neocortex, appearing in all fetal zones starting embryonic day 14. Their distribution changes, with increases in the cortical plate and decreases in intermediate and subventricular zones post-embryonic day 19.
Area of Science:
- Neuroscience
- Developmental Biology
- Neuroanatomy
Background:
- The prenatal development of the neocortex involves the precise migration and differentiation of neuronal populations.
- Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the mammalian brain, crucial for neuronal circuit formation and function.
Purpose of the Study:
- To investigate the temporal and spatial distribution of GABA-immunoreactive neurons in the developing rat neocortex.
- To identify the specific developmental stages and cortical layers where GABA-ergic neurons emerge and change in number.
Main Methods:
- Immunohistochemistry was used to detect GABA-immunoreactive neurons in prenatal rat neocortical tissue.
- Analysis was performed across various embryonic days (E14-E19) and cortical zones.
Main Results:
- GABA-ergic neurons were found in all fetal zones of the cerebral anlage, not just specific layers.
- The first GABA-ergic cells appeared in the plexiform primordium on E14, with a second population emerging in the intermediate zone on E15.
- From E16 onwards, GABA-ergic neurons were observed in the marginal zone, subplate, cortical plate, and ventricular/subventricular zones.
- Post-E19, GABA-ergic neuron numbers increased in the cortical plate but decreased in the intermediate and subventricular zones.
Conclusions:
- GABA-ergic neurons exhibit a widespread distribution within the prenatal rat neocortex from early developmental stages.
- The dynamic changes in GABA-ergic neuron populations across different cortical zones highlight their critical role in neocortical development and circuit maturation.
Abstract:
The present study shows that in the prenatal rat neocortex the GABA immunoreactive neurons are not limited to the marginal, subplate, and intermediate zones, but are also found in all fetal zones of the cerebral anlage. The first GABA-ergic cells are observed on embryonic day 14 in the plexiform primordium. On embryonic day 15, a second population of GABA-ergic cells is observed in the intermediate zone. Beginning on day 16 of gestation and continuing throughout gestation, GABA-ergic neurons are observed in the marginal zone, the subplate zone, the cortical plate, and the ventricular and subventricular zones. Furthermore, while the number of GABA-ergic cells in the cortical plate increases, GABA-ergic neurons in the intermediate zone and subventricular zone decrease in number after embryonic day 19.