“…Despite potential differences in the capacity to form synaptic connexions, given the higher density of spines on human neurons (Benavides-Piccione et al, 2002 ), the rate of local functional connectivity (around 12% in mice, 14% in rats, and 14% in humans) and the number of synapses per connexion (between ~2 and 4) are reported to be comparable between rodents and humans. This similarity extends to the median amplitude (~0.5 mV despite substantial differences between studies and cortical regions, see de Kock and Feldmeyer, 2023 for review), latency, and kinetics of unitary (evoked by the firing of single presynaptic neurons) EPSPs reaching the soma, which show remarkable consistency across a variety of species (human and mouse: Testa-Silva et al, 2014 ; Szegedi et al, 2016 ; Seeman et al, 2018 ; Campagnola et al, 2022 ; Hunt et al, 2023 ; mouse: Oswald and Reyes, 2008 ; Lefort et al, 2009 ; Ko et al, 2013 ; Jouhanneau et al, 2015 ; Luo et al, 2017 ; rat: Mason et al, 1991 ; Hardingham and Larkman, 1998 ; Holmgren et al, 2003 ; Yoshimura et al, 2005 ; Feldmeyer et al, 2006 ; Hardingham et al, 2010 ; macaque and rat: Povysheva et al, 2006 ; cat and rat: Thomson et al, 2002 ). It also predicted that a similarly small number of simultaneously active L2/3-L2/3 synapses (between ~125 and 145) is required to generate a somatic AP in human and rat cell models (Eyal et al, 2018 ).…”