Immunohistochemical methods have been used to study the embryonic and postnatal development of the hormone-producing cells in the adenohypophysis of the lizard Gallotia galloti. In this species, Rathke's pouch is formed between stages 30 to 32 of the embryonic development, although the first sign of immunoreactivity to antisera against adenohypophysial hormones occurs in stage 33 in the pars distalis anlage. These cells derive from the dorsal face of Rathke's pouch and are immunoreactive to anti-ACTH serum. The cytodifferentiation of ACTH and MSH cells occurs in the pars intermedia in stage 34. The TSH cells appear at stage 35 and the gonadotrope cells at stage 37. These cells derive from both the dorsal and ventral face of the Rathke's pouch. The LTH cells are revealed at stage 39 and are only originated from the dorsal face. The STH cells, which come from the dorsal as well as ventral face, are the last secretory cells differentiated just before hatching. During postnatal development an increase and also a redistribution of the immunoreactive cells occur until acquiring the adult distribution.

In lacertids the telencephalic vesicle starts its development at stage E = 30, at which time it is lined by a homogeneous nucleated zone in which particular ventricular zone territories or sulci cannot be distinguished. At stage E = 32 coinciding with the initial development of the anterior dorsal ventricular ridge (ADVR), one may distinguish the ventricular zone b in the dorsolateral wall of the ventricle adjacent to the sulcus lateralis. The ADVR continues growing by incorporation of cells produced in two proliferative zones (zone b and wall of the sulcus lateralis) and appears fully developed in postnatal lizards. Ultrastructural characteristics of young ADVR neurons between stages E-32 and E-33 are typical of those in immature cells. Beginning at stage E-34, some of these neurons appear to be degenerating (pycnotic). Thereafter, neurons of the ADVR develop abundant cytoplasmic organelles and the neuropile grows quickly. Myelination starts in the ADVR between stages E-38 and E-40, but is not observed in other striatal masses in the same period. Vascularization begins and is well developed at E-40. The first synaptic contacts were observed in embryos of stage E=38; they are chiefly axo-dendritic, although some are axo-somatic. Degenerating neurons were found in the ADVR up to hatching. From stage E-40 onward, the ADVR shows a greater and more rapid differentiation than all other striatal nuclei, including the ventral and amygdaloid complex.

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