MAPT and tauopathy: We report three main findings: (i) tau transgenic mice develop an impairment of the cholinergic system and this confirms our previous findings [9,15]; (ii) HMTM treatment partially reversed this impairment and lessened the tauopathy in L1; (iii) combined HMTM and rivastigmine treatment is less efficacious than HMTM monotherapy, with the cholinesterase inhibitor completely blocking any beneficial effects of HMTM in some instances.