The chicken trigeminal ganglion I. An anatomical analysis of the neuron types in the adult,

✍ Scribed by Geraldine C. Gaik; Albert I. Farbman

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 1001 KB
• Volume: 141
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1051410103

✦ Synopsis

Abstract

An anatomical analysis of the chicken trigeminal ganglion was made using light microscopy on specimens prepared by usual chemical fixation or freeze‐drying methods and by electron microscopy. Two types of neurons were consistently seen, dark and light cells. Dark cells contained a dense cytoplasm with Nissl substance distributed evenly throughout, whereas light cells had a less dense cytoplasm containing clumps of Nissl substance. The Nissl bodies in light cells contained only a few small cisternae of granular endoplasmic reticulum as compared with many stacked cisternae in Nissl bodies of dark cells. The ratio of dark to light cells was approximately 62:38 in all regions of the ganglion. Dark cells were consistently smaller than light cells. In the seven‐day old chick, the mean diameters of the dark and light neurons were 21.4 μ and 29.5 μ respectively; in the adult the values were 29.9 μ and 39.7 μ respectively. It is concluded that the dark and light cells belong to two distinct neuronal cell populations.