sentence: Nonetheless , the large number of neurons in our sample , as well as the clear separations between cell classes using either the Ward 's method or the spectral cluster analysis , provides some confidence that major distinctions can still be observed.Notably sparse among our cell types were single ‐ spiking cells , frequently reported in dorsal horn neurons ( Jo et al. 1998 ; Ruscheweyh and Sandk ü hler 2002 ) , and also reported previously in the TNc of rat and mouse ( Sedlacek et al. 2007 ; Alba ‐ Delgado et al. 2015 ) .