EFFECTS OF ESTROGEN REPLACEMENT ON CHOLINE-ACETYLTRANSFERASE AND TRKAMESSENGER-RNA EXPRESSION IN THE BASAL FOREBRAIN OF AGED RATS

The effects of one week of estrogen replacement on choline acetyltrans ferase (ChAT) and trkA mRNA expression are examined in young and aged rodents to determine whether estrogen continues to affect cholinergic neurons in aging brain. Significant increases in ChAT and trkA are obs erved in the nucleus basalis of Meynert (nBM) of both age groups. ChAT expression is also increased in the HDB without changes in trkA expre ssion. Results indicate modulation of ChAT expression by estrogen is r etained in the aged rodent brain and suggests the possibility that cha nges in ChAT expression may be dissociated from concurrent alterations in trkA. (C) 1998 Elsevier Science B.V.