Publication Date:
2009-02-11
Description:
Neurons in the mammalian neocortex are organized into functional columns. Within a column, highly specific synaptic connections are formed to ensure that similar physiological properties are shared by neuron ensembles spanning from the pia to the white matter. Recent studies indicate that synaptic connectivity in the neocortex is sparse and highly specific to allow even adjacent neurons to convey information independently. How this fine-scale microcircuit is constructed to create a functional columnar architecture at the level of individual neurons largely remains a mystery. Here we investigate whether radial clones of excitatory neurons arising from the same mother cell in the developing neocortex serve as a substrate for the formation of this highly specific microcircuit. We labelled ontogenetic radial clones of excitatory neurons in the mouse neocortex by in utero intraventricular injection of enhanced green fluorescent protein (EGFP)-expressing retroviruses around the onset of the peak phase of neocortical neurogenesis. Multiple-electrode whole-cell recordings were performed to probe synapse formation among these EGFP-labelled sister excitatory neurons in radial clones and the adjacent non-siblings during postnatal stages. We found that radially aligned sister excitatory neurons have a propensity for developing unidirectional chemical synapses with each other rather than with neighbouring non-siblings. Moreover, these synaptic connections display the same interlaminar directional preference as those observed in the mature neocortex. These results indicate that specific microcircuits develop preferentially within ontogenetic radial clones of excitatory neurons in the developing neocortex and contribute to the emergence of functional columnar microarchitectures in the mature neocortex.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727717/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727717/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yu, Yong-Chun -- Bultje, Ronald S -- Wang, Xiaoqun -- Shi, Song-Hai -- AS5274/Autism Speaks/ -- R01 DA024681/DA/NIDA NIH HHS/ -- R01 DA024681-01A1/DA/NIDA NIH HHS/ -- R21 MH083624/MH/NIMH NIH HHS/ -- R21 MH083624-01/MH/NIMH NIH HHS/ -- England -- Nature. 2009 Mar 26;458(7237):501-4. doi: 10.1038/nature07722. Epub 2009 Feb 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Developmental Biology Program, Memorial Sloan Kettering Cancer Centre, 1275 York Avenue, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19204731" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Cell Lineage
;
Clone Cells/cytology
;
Mice
;
Neocortex/anatomy & histology/*cytology
;
Neurons/*cytology/*metabolism
;
Synapses/*metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
