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[Repercussions of anterior hypothalamic lesions on nycthemeral variations of plasma thyroxine and corticosterone in the pigeon].
- Source :
-
Comptes rendus des seances de la Societe de biologie et de ses filiales [C R Seances Soc Biol Fil] 1982; Vol. 176 (5), pp. 670-4. - Publication Year :
- 1982
-
Abstract
- Plasma thyroxine and corticosterone levels were determined by competitive protein binding assay, at 3 hr intervals, throughout the photoperiod. Pigeons were kept in controlled environment (21 +/- 1 degree C; 14L6-20: 10D). Intact controls exhibited low thyroxine (T4) and corticosterone (B) levels for the light phase of the photoperiod. Values were rising during the night, up to a peak at 03 hr. Electrolytic lesions were placed bilaterally in either the nucleus anterior medialis hypothalami or the n. preopticus, or the n. supraopticus. Circadian rhythms of both T4 and B were markedly altered in all lesioned pigeons, with a shift of very high T4 values to the morning times and a complete disorganization of B patterns, with very heterogeneous values. The possibility is raised that anterior hypothalamic formations participate in the endogenous oscillator circuitry in birds.
Details
- Language :
- French
- ISSN :
- 0037-9026
- Volume :
- 176
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Comptes rendus des seances de la Societe de biologie et de ses filiales
- Publication Type :
- Academic Journal
- Accession number :
- 6220770