Pigeons working on a multiple fixed ratio 50, fixed interval 10 schedule for food reinforcement were killed at 0, 50, 90, 150 and 240 min after an i.m. injection of 300 mg/kg L tryptophan. The levels of tryptophan, 5 hydroxytryptophan, 5 hydroxytryptamine, 5 hydroxyindole acetic acid, tyrosine, dopamine and norepinephrine were concurrently measured in crude nerve ending fractions (P2) isolated from the telencephalon, diencephalon plus mesencephalon and pons plus medulla oblongata of each pigeon. Increases in 5 hydroxytryptamine levels in the nerve ending fraction from the telencephalon were correlated with the onset of the decreased response rates, whereas a return to baseline responding was correlated with a return to normal serotonin levels in this fraction. Changes in dopamine or norepinephrine were not related to the onset of or recovery from the decreased response rate. One group of pigeons were found which did not display any behavioral disruption even though each had received an injection of L tryptophan; the content of 5 hydroxytryptophan, 5 hydroxytryptamine and 5 hydroxyindoleacetic acid in the nerve ending fraction isolated from the telencephalon of these birds did not differ from control values.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Neurochemistry|
|State||Published - Sep 1976|
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience