Immunocytochemical and ultrastructural study of the rat perireticular thalamic nucleus during postnatal development

Alida Amadeo, Silvia de Biasi, Carolina Frassoni, Barbara Ortino, Roberto Spreafico

Research output: Contribution to journalArticle

Abstract

The perireticular thalamic nucleus (PRT) consists of scattered neurons that are located in the internal capsule adjacent to the gamma aminobutyric acid (GABA)-immunoreactive (ir) reticular thalamic nucleus (RT) and whose number decreases during development. The common feature of PRT neurons in different species is the immunoreactivity for the calcium binding protein parvalbumin (PV), which is also expressed by RT cells. In this study, we analyzed, at the light and electron microscopic level, the distribution and morphology of PV-ir neurons and their relationship with GABA in adult and developing rats. We found that the rostrocaudal distribution and the morphology of PV-ir neurons of the PRT were different at each stage of postnatal development examined. The adult configuration of the PV-ir population in the PRT was achieved at postnatal day 21. With electron microscopy, the developing PRT was observed to contain PV-ir neuronal cell bodies and dendrites contacted by several PV-negative synaptic terminals, some of which were GABA-ir, whereas the adult PRT contained also large PV-ir boutons, generally GABA-ir. Very few GABA-ir neurons were found in the PRT region and only during the first postnatal week, thus indicating that the PV-ir neurons of PRT represent a distinct population from those of RT. Our results demonstrate a morphological, neurochemical, and ultrastructural complexity of the PRT not only during development, but also in adulthood. These findings provide new data supporting the suggested roles of the PRT during postnatal development, and may indicate that in adult life it can play other so far unknown functions.

Original languageEnglish
Pages (from-to)390-401
Number of pages12
JournalJournal of Comparative Neurology
Volume392
Issue number3
DOIs
Publication statusPublished - Mar 16 1998

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Keywords

  • Electron microscopy
  • GABA
  • Parvalbumin
  • Reticular thalamic nucleus
  • Synapses

ASJC Scopus subject areas

  • Neuroscience(all)

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