Alterations in synaptosomal neurotransmitter amino acids in "petit-mal" rats at a daytime and a nighttime.
The synaptosomal fractions of 6 brain areas-olfactory tubercles (OT), frontal cortex (FC), striatum (Sr), amygdala (A), thalamus (Th), hypothalamus (Hy) - have been analyzed for their neurotransmitter amino acids (AA) content in Wistar rats exhibiting "petit-mal" epilepsy (PM-E) and in controls (C). The analysis was carried out at 11 p.m. (nighttime corresponding to the acrophase for the hourly number of spike-wave complexes) and at 11 a.m. (daytime). A day versus night rhythmicity is recorded for synaptosomal inhibitory AA in control and in PM-E rats. However, day versus night variations are more frequent and more prominent in C rats than in PM-E rats. Two day versus night variations exist only in PM-E rats: increases of GABA level in Sr and of Asp in Hy. Differences between PME-and C in synaptosomal AA content are more likely to be present during the nighttime. During this period lower AA values for PM-E rats are found for one or several inhibitory AA in OT, Th, and FC. It seems that the differences between PM-E and C concerning the inhibitory AA correlate with the number of spike-wave discharges. Only in one brain area is there a similar difference for PM-E and C during daytime and nighttime: a decreased GABA content for PM-E rats in OT. The decrease is larger in nighttime than in daytime. This difference may serve as a marker for this epileptic disorder. Moreover, it is in OT that the greatest number of PM-E versus C differences in synaptosomal neurotransmitter AA are observed.(ABSTRACT TRUNCATED AT 250 WORDS)
Simler
S
S
Centre de Neurochimie du CNRS, Strausbourg-Cedex, France.
Ciesielski
L
L
Gobaille
S
S
Mandel
P
P
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D004832:Epilepsy, Absence / Q000378:metabolism*; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000378:metabolism*
D000596:Amino Acids; D018377:Neurotransmitter Agents