1. Unilateral lesions were made in the fimbria of adult rats with a stereotaxically-applied, radio-frequency current. After 3-23 days survival, fresh, unfixed, transverse sections were cut of the forebrain. Half the sections were stained histochemically to show the distribution of acetylcholinesterase (AChE) activity. From the other sections, small, anatomically defined areas were dissected out and assayed for choline acetylase (ChAc) activity (acetyl-CoA: choline-O-acetyltransferase EC2.3.1.6).2. In the fimbria, anterior to the lesion, ChAc activity rises sharply and is still approximately twice the normal after 7 days. In the hippocampus, ChAc activity falls: in most experiments activity on the operated side was 20-40% of that on the control side, but in some experiments values below 10% were obtained. These changes closely parallel those observed in the staining for AChE.3. The results go far towards proving that the hippocampus receives a massive cholinergic innervation via the fimbria. The fibres concerned appear to be those which stain characteristically for AChE and it seems likely that other pathways showing the same histochemical behaviour are also cholinergic.

Acetylcholinesterase↗

PubMed1966

The kinetics of inhibition of the action of thrombin by the fibrinopeptides formed during the clotting of fibrinogen.

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Amino Acids↗

PubMed1966

The distribution of cholinesterases in the cat carotid body.

1. The distribution of acetyl- and butyrylcholinesterase in the carotid body of the cat has been examined histochemically. Studies were made on normal carotid bodies and on carotid bodies from cats in which certain nerves had been cut some time previously. The nerves sectioned were the sinus nerve, the post-ganglionic sympathetic branch of the superior cervical ganglion or the preganglionic cervical sympathetic trunk.2. It was confirmed that more butyrylcholinesterase than acetylcholinesterase is present. Both enzymes are found in three sites: (i) as strands, (ii) as plexuses, (iii) inside a few cells.3. The distribution is unaffected by cutting the sinus nerve or preganglionic cervical sympathetic nerves. Disorganization and depletion of the cholinesterases in the strands and plexuses occurs when the post-ganglionic branch of the superior cervical ganglion is cut. The cholinesterase in cells is unaffected.4. In carotid bodies in which vessels were filled with red blood cells or in which the vascular bed was injected with carmine-gelatine, it was seen that strands and plexuses are associated with blood vessels, and with blood vessels and cells respectively.5. It is suggested that a cholinergic pathway controlling carotid body blood vessels runs in the post-ganglionic cervical sympathetic.

Acetylcholinesterase↗

PubMed1966