FIGURE 2.

Representation of the synapse within the hyperacute phase after impact. (1) Membrane permeability increases soon after impact through the influx/efflux of ions via voltage gated channels or rupturing of the pre-synaptic membrane. (2) The increase in Ca²⁺ primes glutamate filled vesicles and increases the rate of fusion and release of glutamate. (3) Increased and sustained release of glutamate (black dots) into the synaptic cleft activates NMDAr NR2B subunits (purple) and increases post-synaptic concentrations of Ca²⁺. This activates various kinases that phosphorylates AMPA GluR1 subunits (red), further promoting the influx of Ca²⁺. (4) Post-synaptic cytoskeleton alterations occur through phosphorylation (pink dots), with disinhibition of remodeling proteins, such as end-binding protein 3 (green), occurring to allow for the restructuring of the dendritic spine cytoskeleton. (5) Downstream cascades from the influx of Ca²⁺alter microtubule dynamics within the cytoskeleton of the neuron. Created with BioRender.com.