The timeframe for this correlated well with neurite sprouting and synapse stabilization based on previous studies of developing connections in vitro (Soriano et al., 2008). However, in α-syn-hWT pff-treated WT, but not α-syn −/− neurons, the maturation of functional connections never reached the level achieved in PBS-treated cultures, as a significant reduction was observed 10 days after α-syn-hWT pff Fulvestrant treatment (Figure 8F). This functional connectivity was severely compromised 14 days after treatment and the network consisted of just a few sparse connections at this time point

(Figures 8E and 8F). In summary, the formation of insoluble aggregates of endogenous α-syn results in early disruption in coordinated network activity. Later, as more α-syn inclusions develop and propagate throughout the neuron, excitatory tone is decreased and functional connectivity is greatly reduced. Here Talazoparib price we demonstrate that seeds derived from α-syn amyloid fibrils generated with pure recombinant full-length and truncated human WT α-syn, when directly

added to mouse primary hippocampal neurons, are internalized and induce the recruitment of endogenous soluble α-syn into insoluble pathologic LB-like and LN-like α-syn aggregates resembling those found in human synucleinopathies. Indeed the verisimilitude of these α-syn aggregates in cultured mouse neurons to LBs and LNs found in PD brains is striking because they are found in perikarya and extensively in neurites, insoluble, filamentous by EM and immuno-EM, hyperphosphorylated, and ubiquitinated, and they exclude β-syn (Baba et al., 1998, Duda et al., 2000, Fujiwara et al., 2002 and Spillantini et al., 1998). Notably, these aggregates initially formed within axons, sequestering endogenous α-syn away from presynaptic terminals, followed by propagation into the somata. Over time, formation of these α-syn aggregates leads to selective alterations in synaptic proteins, compromises neuronal excitability and connectivity, and culminates in neuron death. Thus, we have developed a neuronal culture model of PD-like α-syn inclusion formation that allows for the dissection of the mechanisms leading to the formation of LBs and LNs, as well as

for studies of the impact of Edoxaban these inclusions on the function and viability of affected neurons. Moreover, since the majority of PD and DLB cases are sporadic and are not caused by mutations or overexpression of α-syn, our neuronal model system provides a means to study the pathogenesis of α-syn in sporadic PD, as well as other α-synucleinopathies. We show that α-syn pffs made from pure, recombinant protein are highly potent in the recruitment of the endogenously expressed protein into LB-like and LN-like α-syn pathology, in contrast to previous studies that have relied on experimental manipulations such as protein overexpression of WT and mutant proteins, and/or extrinsic factors to introduce pffs into cells (Clavaguera et al., 2009, Frost et al., 2009, Guo and Lee, 2011 and Luk et al.