INVERSE CORRELATION OF ACETYLCHOLINESTERASE (ACHE) ACTIVITY WITH THE PRESENCE OF NEUROFILAMENT INCLUSIONS IN DORSAL-ROOT GANGLION NEURONS CULTURED IN THE PRESENCE OF A REVERSIBLE INHIBITOR OF ACHE

We have previously shown that treatment of cultured dorsal root gangli on neurons (DRGN) with a highly specific, reversible acetylcholinester ase (AChE) inhibitor, BW284c51, retards neuritic outgrowth in a dose d ependent manner and is accompanied by the presence of abnormal, perika ryal neurofilament (NF) inclusions in approximately 40% of the cells. Since subpopulations of DRGN have been classified according to their l evels of AChE activity, we have combined immunocytochemical and enzyme histochemical techniques to investigate a possible correlation betwee n AChE activity and the presence of NF inclusion formation. Our result s show that after inhibitor treatment, cells with low levels of AChE a ctivity have a greater percentage of inclusions, with nearly 75% of ce ll with undetectable levels of AChE activity containing inclusions. In contrast, inclusions were present in only 3.2% of cells with high lev els of AChE activity. This inverse relationship between AChE activity and the presence of NF inclusions supports our previous observations t hat this enzyme may have extra-synaptic functions which could affect n euronal development and regeneration.