The Integrative Function of Silent Synapses on Subplate Neurons in Cortical Development and Dysfunction

Conclusion and Open Questions While SPNs as a population of neurons are coming into clearer view, many unknowns remain. SPNs as a group are both the target of initial thalamic inputs but also receive extensive cortical input. In particular, there is an extensive connectivity of SPNs with the cortical plate mediated by NMDAR-only containing “silent” synapses at the earliest ages. These synapses are very sensitive to the resting potential of the cell, thus subtle modulation of the resting potential can modulate their activity and thus their ability to integrate inputs. Activation of silent synapses on SPNs by hypoxia or other insults might be the initial key step in a cascade of events leading to the manifestation of neurodevelopmental disorders. Therefore, interventions that limit the amount of depolarization or NMDAR signaling might be effective in preventing this chain of events. Indeed, hypothermia has been shown to be effective in reducing the effects of hypoxia on cortical neurons (Hiramatsu et al., 1993; Rosen and Morris, 1994) and improves clinical outcomes (Gunn and Bennet, 2008; Jacobs et al., 2013; Papile et al., 2014). It is becoming clear that multiple classes of SPNs exist, but the functional roles of the subclasses are unknown. Moreover, given that SPNs are present in all cortical areas, it is likely that there are functional differences between SPNs in different cortical areas. This has not been explored at all. Most importantly, the role of SP...
Source: Frontiers in Neuroanatomy - Category: Neurology Source Type: research