Fig. 1.

Reports of the glia neuron ratio (GNR) in human brains from the 1960s to the current time. Note the obvious outliers by Kandel's and other's text books with a GNR of 30 (10–50), indicated by purple dots, and the pioneering reports of a GNR of 0.7–1 by Haug (1986), and by Azevedo et al. (2009) that used the isotropic fractionator, indicated by red squares. Data are compiled from the Table 5 published by von Bartheld et al. (2016).