Rendiconti Lincei

, 5:385 | Cite as

Analisi at microscopio confocale laser della plasticitàdelle spine dendritiche

  • Michele di Papa


Si descrive un metodo originale con l’uso del microscopio confocale laser a scansione ed il colorante fluorescente Dil, per studiare la morfologia delle spine dendritiche in culture di neuroni ippocampali di ratto. È stato studiato lo sviluppo in cultura dalla prima alla quarta settimana, e la risposta ad uno stimolo funzionale, condizionando il medium con Tetrodotossina (TTX) o Picrotossina (PTX). La densità delle spine aumenta di 2,7 volte tra la prima e la terza settimana, mentre la lunghezza media cala da 1.6 a 1.1 am. Il rapporto tra il diametro della testa delle spine ed il diametro del collo aumenta, determinando teste maggiori alla terza settimana. La TTX aumenta la lunghezza delle spine, ne diminuisce la densità. La PTX esplica effetto opposto, la forma non cambia. Si ipotizza ehe la densità delle spine costituisce una funzione dei processi di crescita e di in-vecchiamento, e non delle afferenze. La formazione delle spine sembrerebbe indipendente e precedente la sinaptogenesi ehe a sua volta determinerebbe la forma delle spine durante la maturazione. La densità delle spine sarebbe direttamente, e la lunghezza inversamente, correlata aU’attività neuronale.

A confocal laser scanning microscope approach to dendritic spine plasticity


We describe an original method using confocal laser scanning microscopy (CLSM) and the fluorescent marker Dil, to monitor dendritic spine morphology in cultures of rat hippocampal neurons. We performed a developmental analysis from the first to the fourth week in culture, and a functional study conditioning the culture medium with Tetrodotoxin (TTX) or Picrotoxin (PTX). The density of spines increased 2.7 fold between 1 and 3 weeks, while the mean length of the spines decreased from 1.6 to 1.1 am. The ratio between the diameter of the spine head and the diameter of the spine neck increased, resulting in larger spine heads at 3 weeks. The TTX increased spine length and decreased spine density. PTX had the opposite effect. We hypothesize that spine density is a growth and aging related process, and not related to input. Spine formation seems to preceed and be independent of synaptogenesis which is in turn involved in spine shaping during maturation. Spine density seems to be directly and spine length inversely related to neuronal firing rate.

Key words

Dendritic spine Confocal microscopy Dil Picrotoxin Tetrodotoxin 


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Copyright information

© Accademia nazionale dei Lincei 1994

Authors and Affiliations

  • Michele di Papa
    • 1
  1. 1.Istituto di Anatomia Umana Normale Facoltà di MedicinaChirurgia LT Universitédegli Studi di Napoli Via L. ArmanniNapoli

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