EEG changes following increased blood-brain barrier permeability under long-term immobilization stress in young rats.
A continuous 8 h of immobilization stress in conscious young rats increased the blood-brain barrier (BBB) permeability to 131I-sodium in 12 out of 14 brain regions studied. A flattening of electroencephalographic (EEG) activity was noted during this time period. The mean cerebral blood flow (CBF) was reduced by 17% (during this time period) but the regional flow reduction was not related to the regional increase in BBB permeability. On the other hand, a correlation was observed between increased plasma and brain 5-HT levels and increased BBB permeability. p-Chloro-phenylalanine (p-CPA) pretreatment has prevented the occurrence of increased BBB permeability, and the flattening of EEG activity as well as 5-HT levels in plasma and brain. These results suggest that the long-term immobilization stress induces causally related sequential events in rats: enhancement of circulating 5-HT, impairment of BBB, free access of 5-HT into the brain, and eventually flattening of EEG.
Sharma
H S
HS
Department of Physiology, Banaras Hindu University, Varanasi, India.
Dey
P K
PK
D000818:Animals; D001812:Blood-Brain Barrier; D001921:Brain / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D004569:Electroencephalography; D005260:Female; D010134:Fenclonine / Q000008:administration & dosage; D007103:Immobilization; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000097:blood; D013312:Stress, Physiological / Q000097:blood / Q000503:physiopathology*
D012701:Serotonin; D010134:Fenclonine