Comparative mapping of acetylcholinesterase and reduced nicotinamide adenine dinucleotide diaphorase in the rabbit dorsal thalamus.

The distribution of acetylcholinesterase and reduced nicotinamide adenine dinucleotide (NADH) diaphorase enzymatic activities was mapped histochemically in the dorsal thalamus of the rabbit. A comparison of the resulting patterns helped in the histochemical delimitation of a number of nuclei, as well as in the detection of some subdivisions, that showed differential expression of these enzymes. It was observed that AChE and NADH diaphorase tend to appear in a complementary fashion in many dorsal thalamic neuropiles, so that intense activity of the one was accompanied by low activity of the other. However, coincident expression of both enzymes was also obtained in a small number of areas. The correlation of these patterns with other chemo-architectonic and hodologic data does not yet disclose an explanation of these regularities, which however suggest some functional significance.