0000000000225098
AUTHOR
Jorge J. Palop
Early histological maturation in the hippocampus of the guinea pig.
The vesicular zinc-rich synaptic systems of the principal neurons of the hippocampus are well developed in newborn guinea pigs, a precocial species. In addition, alvear and fimbrial myelinated fibers as well as significant inhibitory interneurons (i.e. somatostatin, parvalbumin and opioid immunoreactive hippocampal interneurons) are also well developed. On the contrary, neither vesicular zinc synapses nor myelinated fibers nor the above mentioned immunoreactive interneurons are detectable in newborn specimens of other related altricial species such as rats or rabbits. These data suggest that early maturation of a highly integrative center related to cognitive map building such as the hippoc…
Cytochemical techniques for zinc and heavy metals localization in nerve cells
Zinc is one of the most abundant oligoelements in the living cell. It appears tightly bound to metallothioneins, loosely bound to some metalloproteins and nucleic acids, or even as free ion. Small amounts of zinc ions (in the nanomolar range) regulate a plentitude of enzymatic proteins, receptors, and transcription factors; thus, cells need accurate homeostasis of zinc ions. Some neurons have developed mechanisms to accumulate zinc in specific membrane compartments ("vesicular zinc") which can be revealed using histochemical techniques. This article is a short report on the different direct-indirect experimental approaches for zinc and heavy metal detection in neurons. Substances giving a b…
Zinc-positive presynaptic boutons of the rabbit hippocampus during early postnatal development
Abstract The evolution of vesicular zinc-containing boutons in the developing rabbit hippocampus has been studied during early postnatal life using the selenite–Danscher histochemical method. By P3, large immature mossy fiber boutons with labeled synaptic vesicles were seen in the hilus of the dentate gyrus and in the stratum lucidum of the CA3–CA4 hippocampal areas. After P5, smaller boutons with labeled vesicles were identified in the stratum oriens and stratum radiatum of all hippocampal areas, and even transiently in the stratum lacunosum of P6 animals. Vesicular zinc-containing boutons increased in number and underwent ultrastructural maturation; light microscope densitometric–volumetr…