Data di Pubblicazione:
2011
Citazione:
Neural System Rearrangement during the Metamorphosis of the Hydroid Clava multicornis / R. Pennati, A. Dell'Anna, P. Pagliara, G. Scarì, G. Zega, S. Piraino, F. De Bernardi. - In: EUROPEAN JOURNAL OF HISTOCHEMISTRY. - ISSN 1121-760X. - 55:Suppl. 1(2011 Jun), pp. 12-12. ((Intervento presentato al 34. convegno National Congress of the Italian Society of Histochemistry tenutosi a S. Benedetto del Tronto nel 2011.
Abstract:
The planula larva of the hydroid Clava multicornis has a
complex nervous system. It is characterized by the presence of
distinct populations of neural elements concentrated at the
anterior end representing the sensory pole of this life stage. The
neurons can be identified by the presence of different neuropeptides:
GLWamide positive cells are arranged in a domelike
organization in the anterior most region and are followed
by a belt of RFamide positive ones, both types being connected
to a basiectodermal anterior plexus.1 During the metamorphosis,
the larva attaches to the substrate with the anterior end
that develops into the basal foot region of the polyp, while the
posterior end forms the oral region. In the polyp of the hydrozoan
Hydractinia echinata GLWamide and RFamide positive
neurons are concentrated around the mouth and in the tentacles,
at the opposite side respect to the position occupied in the
larva.2 To elucidate the fate of the neural cells in C. multicornis,
we investigated the distribution pattern of GLWamide and
RFamide positive sensory cells at different stages of metamorphosis.
We observed that immunoreactivity is still present at
the anterior end of the larva during early settlement, but gradually
disappeared through the following stages of metamorphosis.
Only in late stages positive cells appeared around the
mouth of the newly formed polyp. By TUNEL assay, apoptotic
nuclei were identified in the anterior end of the settled larva, in
the same region occupied by sensory cells. These results suggest
that at least part of the neurons of the larva degenerates during
metamorphosis by apoptosis and that at least part of the
adult nervous system is formed by de novo differentiation.
Understanding how the nervous system is rearranged during
the metamorphosis of basal metazoans can help to elucidate
mechanisms of neural plasticity in higher metazoans
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
R. Pennati, A. Dell'Anna, P. Pagliara, G. Scarì, G. Zega, S. Piraino, F. De Bernardi
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