An autoradiographic analysis of the development of the chick trigeminal ganglion

Abstract

The avian trigeminal ganglion, which is embryonically derived from the neural crest and epidermal placodes, consists of two topographically segregated classes of immature neurons, large and small, during the second week of incubation, and two neuronal cell types, dark and light, interspersed throughout the mature ganglion. In order to establish the times of terminal mitosis of trigeminal sensory neurons, embryos were treated with [3H]thymidine during the first week of incubation and their ganglia fixed on embryonic day 11. The embryonically large, distal, placodal-derived neurons are generated between days 2 and 5, while the small, proximal, neural crest-derived neurons are formed mostly between days 4 and 7. By comparing the locations of labeled cells in ganglia treated with isotope but fixed on day 18 of incubation with their 11-day counterparts, we have proved that there are no morphogenetic rearrangements of neurons during the final week of incubation. Thus, no unique relationship exists between the two neuron types in the mature ganglion and the two cell classes in the immature trigeminal. Therefore, both the light and the dark neurons in the mature trigeminal ganglion arise from neural crest as well as placodal primordia.

Loss of Elp1 disrupts trigeminal ganglion neurodevelopment in a model of familial dysautonomia

“…Therefore, anatomical position is an unreliable tool for predicting placodal versus neural crest lineage in the mouse trigeminal ganglion. Interestingly, studies in the chick trigeminal ganglion attribute large cell body diameter to potential placode lineage, while small diameter cells have been linked to neural crest lineage ( d’Amico-Martel and Noden, 1980 ; D’Amico-Martel and Noden, 1983 ). Coincidently, murine TrkB and TrkC neurons tend to have larger cell bodies compared to small-diameter TrkA-expressing neurons ( Fariñas et al, 1998 ; Huang et al, 1999a ).…”

“…Shortly after differentiation, trigeminal ganglion neuron subtypes are discernable by mutually exclusive expression of tropomyosin receptor kinase (Trk) receptors, TrkA, TrkB, or TrkC, which are required for target innervation and long-term survival ( Huang et al, 1999a ; Wilkinson et al, 1996 ; Scott-Solomon and Kuruvilla, 2018 ; Davies, 1997 ; Reichardt, 2006 ; Huang et al, 1999b ). Importantly, Trk expression generally correlates with the ultimate sensory modality encoded by a particular neuron; for example, small-diameter TrkA neurons are typically associated with pain and temperature perception, while large-diameter TrkB and TrkC neurons are usually mechanoreceptors that sense touch, pressure, and vibrations ( Mu et al, 1993 ; Genç et al, 2005 ; d’Amico-Martel and Noden, 1980 ; D’Amico-Martel and Noden, 1983 ; Davies and Lumsden, 1984 ).…”

Neural crest cell-placodal neuron interactions are mediated by Cadherin-7 and N-cadherin during early chick trigeminal ganglion assembly

“…8, [33][34][35] While these cells give rise to distinct derivatives, they will both form sensory neurons of the trigeminal ganglion, innervating much of the head and face to relay information related to pain, touch, and temperature to the central nervous system. [3][4][5] The cellular origin of the trigeminal ganglion has been known for decades 7,10,36 ; however, molecular mechanisms mediating early interactions between neural crest cells and placodal neurons to build the Figure 5. Identical cadherin-expressing GRASP constructs possessing complementary GFP domains reconstitute GFP in cis.…”

Making a head: Neural crest and ectodermal placodes in cranial sensory development

“…The trigeminal ganglion is comprised of both neural crest and ectodermal placode cells. Once these cells differentiate, they are regionalized to both the proximal and distal region of the ganglion, respectively [52,148]. First, the trigeminal placodes produce neurons in the distal region of both the maxillo-mandibular and ophthalmic region of the ganglion.…”

“…First, the trigeminal placodes produce neurons in the distal region of both the maxillo-mandibular and ophthalmic region of the ganglion. These neurons lay down a structural template that the neural crest then fills in with its neuronal derivatives proximally ( [52,148,159]; reviewed in [232]). Therefore, not only do placode cells give rise to neurons in the distal region but also neural crest cells differentiate and give rise to neurons in the proximal region of the ganglion.…”