Neuronal circuits of the neocortex, Douglas and Martin (2004)
- Layer I mostly receives distant cortical "feedback" and subcortical projections.
- Organization of cortical lamina, "is to generate a scaffold that constrains the way in which neurons can connect. This principle alone may be the reason why the brain makes such extensive use of cortical structures. A corollary of this is that cortical structures may allow neurons to connect with each other with the minimum use of wire."
- the basal dendrites radiating from the cell body form about 90% of the dendritic length of any cortical pyramidal neuron (Larkman 1991).
Experience-dependent structural synaptic plasticity in mammalian brain, Holtmaat and Svoboda (2009)
- Thalamocortical boutons are very stable. L5 and L2/3 boutons show 20% turnover in 1 month. About 20% turnover for spines as well.
- Greater turnover of cortical dendritic spines vs axonal boutons. Suggests two are not coupled. Probably due to fact that about half of all new spines hook up with existing bouton (2 spines, 1 bouton).
- Spine does not = synapse! In fact, only 30% of two-day-old spines had formed a synapse (although spines > 4 days old almost always have synapse).