Behavioral and neurochemical alterations evoked by p-Chlorophenylalanine application in rats examined in the light-dark crossing test.
The aim of the present study is to examine the effects of serotonin synthesis inhibition with p-Chlorophenylalanine (p-CPA) in rats on (1) anxiety behavior examined in the light-dark crossing test and, (2) regional brain concentration of monoamines (NA, DA and 5-HT) and their metabolites (MHPG, DOPAC, HVA and 5-HIAA) as well as GABA in the hypothalamus, amygdala, hippocampus, midbrain central gray matter and the frontal cortex. Treatment of animals with p-CPA produced a significant increase in time out from the illuminated part of the chamber and in time of locomotor activity in the illuminated part of the chamber. HPLC analysis showed a significant reduction of 5-HT and 5-HIAA concentration in all examined brain regions with the exception of the frontal cortex. Additionally, a significant decrease in DA and its metabolites, DOPAC and HVA occurred in the hypothalamus and amygdala. Moreover, we observed a significant decrease in frontal cortex NA concentration after p-CPA administration. The results of our study suggest that administration of p-CPA is effective in reduction of anxiety through depletion of 5-HT accompanied by diminution of catecholamines, especially DA and its metabolites in the main emotional brain regions.
Koprowska
M
M
Department of Neurophysiology, University of Lódź, Poland.
Krotewicz
M
M
Romaniuk
A
A
Strzelczuk
M
M
Wieczorek
M
M
D000818:Animals; D001007:Anxiety / Q000523:psychology*; D001522:Behavior, Animal / Q000187:drug effects*; D015306:Biogenic Monoamines / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects*; D010134:Fenclonine / Q000494:pharmacology*; D008029:Lighting; D008297:Male; D051381:Rats; D012702:Serotonin Antagonists / Q000494:pharmacology*
D015306:Biogenic Monoamines; D012702:Serotonin Antagonists; D010134:Fenclonine