Number and distribution of neurons in leech segmental ganglia.

摘要: The number of neurons and their distribution were determined for specific segmental ganglia from the nerve cord four different species leech. Quantitative data obtained by using computer-aided techniques analysis structure serially sectioned or whole-mounted tissue. studied Hirudo medicinalis, Macrobdella decora, Haemopis marmorata (family Hirudinidae), Haementeria ghilianii Glossophoniidae). Two sets in each species: middle (9, 10, 11) sex (5 6). ganglia, as well rest 21 except 5 6, are thought to be quite similar. associated with sexual organs appear have more neurons. reported here indicate that: a) a specified ganglion varies one two percent animal given species; b) particular leech approximately same neurons, variation also within percent; c) Hirudo, Macrobdella, nearly (about 400), but those some 20 fewer 380); d) few hundred than exact varying according species, only about ganglia; e) neuronal somata among glial packets is not symmetric midsaggital plane animal, packet variable; f) geometry generally invariant, occasionally found abnormal positions.