Investigating Early Formation of the Cerebral Cortex by In Utero Electroporation: Methods and Protocols

Kozulin, Peter; Almarza, Gonzalo; Gobius, Ilan; Richards, Linda J.

doi:10.1007/978-1-4939-3014-2_1

Cited by 2 publications

(2 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3D). In accordance with gene electroporation studies in mouse (31) and dunnart (30), these peaks approximately coincided with the birth of deeper layer neurons for CTIP2 (stages 19 to 20: embryonic day [E]11 to E13 in mice, and postnatal day [P]4 to P11 in dunnarts) and upper layer neurons for SATB2 (stages 22 to 23, E13.5 to E15.5 in mice, and P17 to P23 in dunnarts). We therefore selected stages 20 and 23 in both species for subsequent electroporation-based transfections of deeper layer CTIP2-expressing neurons and upper layer SATB2-expressing neurons, respectively.…”

Section: Cells Expressing Satb2 and Ctip2 Mrna And Protein Populate Ssupporting

confidence: 80%

Differential timing of a conserved transcriptional network underlies divergent cortical projection routes across mammalian brain evolution

Paolino

Fenlon

Kozulin

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

A unique combination of transcription factor expression and projection neuron identity demarcates each layer of the cerebral cortex. During mouse and human cortical development, the transcription factor CTIP2 specifies neurons that project subcerebrally, while SATB2 specifies neuronal projections via the corpus callosum, a large axon tract connecting the two neocortical hemispheres that emerged exclusively in eutherian mammals. Marsupials comprise the sister taxon of eutherians but do not have a corpus callosum; their intercortical commissural neurons instead project via the anterior commissure, similar to egg-laying monotreme mammals. It remains unknown whether divergent transcriptional networks underlie these cortical wiring differences. Here, we combine birth-dating analysis, retrograde tracing, gene overexpression and knockdown, and axonal quantification to compare the functions of CTIP2 and SATB2 in neocortical development, between the eutherian mouse and the marsupial fat-tailed dunnart. We demonstrate a striking degree of structural and functional homology, whereby CTIP2 or SATB2 of either species is sufficient to promote a subcerebral or commissural fate, respectively. Remarkably, we reveal a substantial delay in the onset of developmental SATB2 expression in mice as compared to the equivalent stage in dunnarts, with premature SATB2 overexpression in mice to match that of dunnarts resulting in a marsupial-like projection fate via the anterior commissure. Our results suggest that small alterations in the timing of regulatory gene expression may underlie interspecies differences in neuronal projection fate specification.

show abstract

Section: Cells Expressing Satb2 and Ctip2 Mrna And Protein Populate Ssupporting

confidence: 80%

Differential timing of a conserved transcriptional network underlies divergent cortical projection routes across mammalian brain evolution

Paolino

Fenlon

Kozulin

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Here, we employed a highly replicable labelling technique, involving in utero electroporation of fluorescent proteins and high-resolution axonal quantifications, to investigate these possibilities in a model that contains both homotopic and heterotopic callosal projections: the mouse somatosensory system. The advantages of this method are that it can be targeted to label specific populations of neurons in the cortex, it provides whole cell fills and it avoids the presence of a fluorescent bolus at the injection site (Kozulin et al, 2016). By analysing contralateral axon development at multiple time points and under paradigms of sensory manipulation, we present a scheme that incorporates elements from previously conflicting hypotheses, which could serve as a new experimental model to study bilateral brain wiring under healthy and pathological conditions.…”

Section: Introductionmentioning

confidence: 99%

The anatomy, organisation and development of contralateral callosal projections of the mouse somatosensory cortex

Fenlon

Suárez

Richards

2017

Brain and Neuroscience Advances

Self Cite

View full text Add to dashboard Cite

Background: Alterations in the development of neuronal connectivity can result in dramatic outcomes for brain function. In the cerebral cortex, most sensorimotor and higher-order functions require coordination between precise regions of both hemispheres through the axons that form the corpus callosum. However, little is known about how callosal axons locate and innervate their contralateral targets. Methods: Here, we use a combination of in utero electroporation, retrograde tracing, sensory deprivation and high-resolution axonal quantification to investigate the development, organisation and activity dependence of callosal axons arising from the primary somatosensory cortex of mice. Results: We show that distinct contralateral projections arise from different neuronal populations and form homotopic and heterotopic circuits. Callosal axons innervate the contralateral hemisphere following a dorsomedial to ventrolateral and region-specific order. Furthermore, we identify two periods of region-and layer-specific developmental exuberance that correspond to initial callosal axon innervation and subsequent arborisation. Early sensory deprivation affects only the latter of these events. Conclusion: Taken together, these results reveal the main developmental events of contralateral callosal targeting and may aid future understanding of the formation and pathologies of brain connectivity.

show abstract

Investigating Early Formation of the Cerebral Cortex by In Utero Electroporation: Methods and Protocols

Cited by 2 publications

References 26 publications

Differential timing of a conserved transcriptional network underlies divergent cortical projection routes across mammalian brain evolution

Differential timing of a conserved transcriptional network underlies divergent cortical projection routes across mammalian brain evolution

The anatomy, organisation and development of contralateral callosal projections of the mouse somatosensory cortex

Contact Info

Product

Resources

About