Effect of filaments within the synaptic cleft on the response of excitatory synapses simulated by computer experiments

Stochastic, structural and functional factors influencing AMPA and NMDA synaptic response variability: a review

“…The space between the inner and outer cylinder is filled with fibrils (see Figure 2) that connect pre-and post-synaptic membrane cell [9,25,26]. Fibrils are neuroligin-neurexin complexes and influence the free diffusion of glutamate molecules in the cleft [9]. Their role seems to be fundamental in synaptic development and maturation ( [27], and references therein) and the disruption of their arrangement seems to be connected with autism and other mind-associated conditions [1,28].…”

“…Other models consider a much complex structure of the synaptic space (see for example [5,16]). Our recent version of the synaptic model has a much more detailed and complex geometry that considers three main compartments for diffusion (vesicle, fusion pore and synaptic cleft), the 3D spaces occupied by receptors in the cleft and also the presence of fibrils [4,9,12,13,17,18,19]. A schematic representation of our synaptic space model is shown in in Figure 2.…”

“…Since diameter of the spine head can be up to 1 μm [14], we choose a conservative value of 400 nm. The space between the inner and outer cylinder is filled with fibrils (see Figure 2) that connect pre-and post-synaptic membrane cell [9,25,26]. Fibrils are neuroligin-neurexin complexes and influence the free diffusion of glutamate molecules in the cleft [9].…”

“…Although the structure of the glutaminergic synapse appears to be simple in principle, its geometry and the diffusion of transmitters have several infrastructure limitations that need to be accounted for in a correct simulation [6][7][8][9][10][11][12][13]. Several models oversimplify the synaptic space, and the diffusion mechanism, just assuming the instantaneous release of a given amount of glutamate molecules at the top of a parallelpiped, and an array of receptors at its bottom [14,15].…”

“…Their role seems to be fundamental in synaptic development and maturation ( [27], and references therein) and the disruption of their arrangement seems to be connected with autism and other mind-associated conditions [1,28]. Fibrils are modelled as thin cylinders with a diameter of 14 nm (see Figure 1 in [9] and references reported therein) and seperated from each other by 6-22 nm.…”