By using immunocytochemistry we tested whether neurotransmitters, and enzymes specific to neurotransmitters synthesis are rhythmically expressed in the suprachiasmatic nuclei of the hypothalamus of Ruin lizards Podarcis sicula either kept in light-dark cycles or constant darkness. Within the suprachiasmatic nuclei, prominent 24 h rhythms under 12:12 light-dark cycles were found for vasoactive intestinal polypeptide (VIP) and for tyrosine hydroxylase (TH). Peaks of both VIP and TH fell in the light phase of the cycle. Rhythmic expression of TH persisted under constant temperature and darkness, demonstrating the existence of circadian rhythms of TH in the suprachiasmatic nuclei. No rhythmic expression of neurotransmitters and related compounds was found in the periventricular nuclei, the supraoptic nuclei, and the rest of the hypothalamus. Our data are the first demonstration of rhythmic expression of neurotransmitters and related compounds in the suprachiasmatic nuclei of a non-mammalian vertebrate. The demonstration of a diurnal peak of VIP in a diurnal reptile—vs. nocturnal peak of VIP typical of nocturnal mammals—provides new information for comparative studies on the circadian physiology of the suprachiasmatic nuclei across vertebrate classes and their adaptation strategies to different temporal niches.

Daily and circadian rhythms of neurotransmitters and related compounds in the hypothalamic suprachiasmatic nuclei of a diurnal vertebrate

MAGNONE, Maria Chiara
Primo
;
BERTOLUCCI, Cristiano
Secondo
;
PIAZZA, Francesca
Penultimo
;
FOA', Augusto Giuseppe Lorenzo
Ultimo
2003

Abstract

By using immunocytochemistry we tested whether neurotransmitters, and enzymes specific to neurotransmitters synthesis are rhythmically expressed in the suprachiasmatic nuclei of the hypothalamus of Ruin lizards Podarcis sicula either kept in light-dark cycles or constant darkness. Within the suprachiasmatic nuclei, prominent 24 h rhythms under 12:12 light-dark cycles were found for vasoactive intestinal polypeptide (VIP) and for tyrosine hydroxylase (TH). Peaks of both VIP and TH fell in the light phase of the cycle. Rhythmic expression of TH persisted under constant temperature and darkness, demonstrating the existence of circadian rhythms of TH in the suprachiasmatic nuclei. No rhythmic expression of neurotransmitters and related compounds was found in the periventricular nuclei, the supraoptic nuclei, and the rest of the hypothalamus. Our data are the first demonstration of rhythmic expression of neurotransmitters and related compounds in the suprachiasmatic nuclei of a non-mammalian vertebrate. The demonstration of a diurnal peak of VIP in a diurnal reptile—vs. nocturnal peak of VIP typical of nocturnal mammals—provides new information for comparative studies on the circadian physiology of the suprachiasmatic nuclei across vertebrate classes and their adaptation strategies to different temporal niches.
2003
Magnone, Maria Chiara; Bertolucci, Cristiano; Piazza, Francesca; Foa', Augusto Giuseppe Lorenzo
File in questo prodotto:
File Dimensione Formato  
1-s2.0-S0006899303025678-main.pdf

solo gestori archivio

Descrizione: Full text editoriale
Tipologia: Full text (versione editoriale)
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 949.17 kB
Formato Adobe PDF
949.17 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/1202118
Citazioni
  • ???jsp.display-item.citation.pmc??? 1
  • Scopus 5
  • ???jsp.display-item.citation.isi??? 3
social impact