Showing papers by "Ann M. Graybiel published in 1982"
TL;DR: BuChE or its endogenous substrate may be a neuroactive substance in the primate brain and is independent of AChE both in its normal distribution in the lateral geniculate body and striate cortex and in the response it shows to eye enucleation.
Abstract: Cholinesterases in brain tissue are divided into two main classes: ‘true’ cholinesterases (acetylcholinesterase, AChE, EC 3.1.1.7), which preferentially hydrolyse the neurotransmitter acetylcholine; and ‘pseudocholinesterases’ (for example, butyrylcholinesterase, BuChE, EC 3.1.1.8), which preferentially hydrolyse higher choline esters1. AChE is found at peripheral and central cholinergic synapses, is known to be the degradative enzyme of the cholinergic mechanism and may also have other functions in the central nervous system1–3. In contrast to AChE, the pseudocholinesterases have been assigned no certain function in neural transmission and initially were thought to occur mainly in neuroglia, Schwann cells and vascular endothelia1,4. Pseudocholinesterase activity has since been found in neurones and neuropil in several brain regions1,4,5, however, and in the superior cervical ganglion, BuChE has been localized to postsynaptic membranes6 and shown to exist in stable molecular forms corresponding to each of the known molecular forms of true cholinesterase7. These observations have led to the alternative interpretations that the pseudocholinesterases are either metabolic precursors of AChE8 or that they have functions closely related to those of AChE5,7 while being independent of true cholinesterases. We have directly compared the distributions of BuChE and AChE in the central visual pathway of the primate, a neural system in which anatomical and functional compartmentalization is well known9. We demonstrate here that the histochemical localization of Pseudocholinesterase rivals that of AChE in terms of specificity, and that BuChE is independent of AChE both in its normal distribution in the lateral geniculate body and striate cortex and in the response it shows to eye enucleation. We conclude that BuChE or its endogenous substrate may be a neuroactive substance in the primate brain.
109 citations
TL;DR: It is concluded that the histochemically distinct striosomal patch-works observed in the acetylcholinesterase and enkephalin preparations correspond to ontogenetic units of the striatum.
Abstract: Neurons being generated in the striatum of 10 fetal cats were pulse labeled by injection of [3H]thymidine directly into the maternal uterus at times ranging between the 22nd and 30th days (E22-E30) of the 65-day gestational period. Many of the striatal neurons labeled during this interval were found, at adolescence, to form 100- to 600-mum-wide cell clusters in the caudate nucleus. In E24-E30 specimens, we compared the distributions of these cell clusters with the locations of patches of low acetylcholinesterase activity and high enkephalin immunoreactivity (the "striosomes') visualized in serially adjoining sections. We found precise matches between most of the cell clusters and the acetylcholinesterase-poor enkephalin-rich zones, regardless of the embryonic age at which exposure to the [3H]thymidine had occurred. We conclude that the histochemically distinct striosomal patch-works observed in the acetylcholinesterase and enkephalin preparations correspond to ontogenetic units of the striatum.
99 citations