On the distribution of acetylcholinesterase in the medulla oblongata of hedgehog (Paraechinus micropus).

The paper deals with the distribution of acetylcholinesterase (CHO-A) in the various nuclei, tracts and fibrous bundles of the medulla oblongata of hedgehog. The main highlights of the study are: 1. The cranial nerve nuclei such as nucleus n. hypoglossi, nucleus dorsalis n. vagi, nucleus tractus spinalis n. trigemini, nucleus n. facialis, nucleus abducentis and nucleus ambiguus demonstrate strong activity of the enzyme irrespective of their motor or sensory nature. 2. The nucleus vestibularis medialis, nucleus vestibularis lateralis and nucleus cochlearis dorsalis exhibit activity of high order, which indicates that the auditory system in the animal is quite active. 3. All the reticular nuclei demonstrate positive activity in neurons only, whereas the neuropil is completely free from enzymatic activity. 4. The fibers, tracts and blood vessels are completely free from enzymatic activity. The functional significance of CHO-A has been discussed in relation to its localization in different nuclei, tracts and fibrous bundles.