TY - JOUR A1 - , T1 - Subdivisions of the human substantia nigra using AChE histochemistry JO - Eur. J. Anat. SN - 1136-4890 Y1 - 1998 VL - 2 SP - 115 EP - 122 UR - http://www.eurjanat.com/web/paper.php?id=98020012 KW - Acetylcholinesterase - substantia nigra - human - hístochernístry - basal ganglia N2 - The present work describes the neurochernical activity detected in the nigral complex of the adult human using the acetylcholinesterase histo­ chemical technique. Such activity is seen at cell level in the pigmented neurons of the pars com­ pacta of the substantia nigra, and, to a lesser degree, in the paranigral neuronal groups (ven­ tral tegmental area and retrorubral field). There is also considerable enzymatic activity in the neu­ ropil of the substantia nigra. However, the pars lateralis and overall the ventromedial portion of the substantia nigra present a relativeJy low acetylcholinesterase content, though both have so me acetylcholinesterasic neuronal bodies. A series of studies in different species suggested that in the substantia nigra, AChE is released almost exdusively from dopaminergic nígrostria­ tal neurons and precisely from their dendrites, which protrude widely into de pars reticulata. In addition, previous findings made in the cat and in the monkey reported a direct correlation bet­ ween nigral AChE activity and nigrostriatal con­ nections. The non-uniform distribution of AChE activity within the human nigral complex repor­ ted here may indicate the modular organization of the intrinsic neurons of the substantia nigra and their mesostriatal projections. ER -