Conclusions and Discussion [chapter]

2016 Critical Management Studies  
Clancy et al. Remarks, main conclusions and discussion Frontiers in Neuroantomy www.frontiersin.org March 2010 | Volume 4 | Article 7 | 2 6. Both GABAergic and subplate populations include numerous and diverse morphological subsets that are different from the more prevalent cortical pyramidal neurons (although each population may include cells with pyramidal morphology), and both populations contain a subset whose projections may travel long distances, sometimes crossing areal boundaries, as
more » ... l boundaries, as well as a subset that focuses projections on cortical layer I. Both populations are similarly heterogeneous in their electrophysiological properties and in the numerous signaling chemicals they sequester. Moreover, subsets may share a common non-cortical birthplace in the ganglionic eminences, raising the possibility that some may descend from similar sets of precursors. Supporting this notion, both populations use somewhat similar molecular modes of migration, different from the mechanism used by pyramidal cells. 7. Although the contribution of the GABAergic interneurons to cortical function is undisputed, and the critical role of the subplate in cortical development is well-accepted, conventional models of mature cognitive function do not yet incorporate contributions of either the projection GABAergic or the persisting subplate neurons. When numbers are reduced compared to other neural populations, there may be a tendency to simply dismiss those that persist as "sparse," "remnants," or "relics". Unfortunately, such terminology implies a fairly unessential function, and it seems important to avoid such categorization until additional information on their function is available. 8. The mathematical principles underlying small-world networks suggest that sparse connectivity is a plausible design underlying important cognitive function. Long-range inhibition, even from relatively sparse connections, can be a potent network component. In small-world networks, clusters of cells link to their nearest neighbors, while some connect to distant clusters. This pattern can serve as the basis for a surprisingly strong communication network, especially when it is amplifi ed by local input, as is likely the case for both the long-range GABAergic and the persisting subplate populations. 9. In a series of previous studies, mathematical models have been used to successfully identify both similarities and relative differences in the timing of neural "events" when comparing primate and nonprimate development. For the purpose of this review, "neural events" are defi ned as milestones pertaining to neural development such as the post conception (PC) date when neurons destined for the various cortical layers are generated. Mathematical approaches are valid because despite species differences, including differences in the duration of development, the size of most brain regions scales similarly across species. Central to this meta analysis, the timing of events that occur in most neural regions is remarkably conserved. 10. The most pragmatic application of statistical modeling is that neural events empirically derived in one species can be compared and successfully applied to another. Therefore, given the potentially important contributions of the long distance GABAergic and persisting subplate populations, we reasoned any additional information about these two populations, including comparative cross-species data, is likely to
doi:10.1108/s2059-65612016015 fatcat:6aksnrlrjva4zb4zljidvuw2dy