Premium
Cerebral O 2 consumption in young Eker rats, effects of GABA blockade: implications for autism
Author(s) -
Weiss Harvey R.,
Liu Xia,
Chi Oak Z.
Publication year - 2008
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2008.01.002
Subject(s) - cerebral blood flow , bicuculline , endocrinology , cerebral cortex , medicine , hippocampus , tuberous sclerosis , autism , cortex (anatomy) , antagonist , chemistry , anesthesia , biology , receptor , neuroscience , pathology , psychiatry
Since there is a strong correlation between tuberous sclerosis and autism, we used a tuberous sclerosis model (Eker rat) to test the hypothesis that the increased regional cerebral O 2 consumption in the Eker rat might be associated with autism. We also examined whether this increased cerebral O 2 consumption was related to changes in the activity of the gamma‐aminobutyric acid (GABA) inhibitory system. Young (4 weeks) male control Long Evans ( n = 14) and Eker ( n = 14) rats (70–100 g) were divided into control and bicuculline (1 mg/kg/min for 2 min then 0.1 mg/kg/min for 13 min, GABA A receptor antagonist) treated animals. Cerebral regional blood flow ( 14 C‐iodoantipyrine) and O 2 consumption (cryomicrospectrophotometry) were determined in isoflurane anesthetized rats. We found significantly increased basal O 2 consumption in the cortex (6.3 ± 0.7 ml O 2 /min/100 g Eker vs. 5.1 ± 0.2 ml O 2 /min/100 g control), hippocampus and cerebellum, but not the pons. Regional cerebral blood flow was also elevated in the cortex and hippocampus in Eker rats at baseline, but cerebral O 2 extractions were similar. Bicuculline significantly increased O 2 consumption in the cortex (6.5 ± 0.3) and all other regions of the control rats, but had no effect on cortex (5.9 ± 1.5) or other regions of the Eker rats. Cerebral blood flow followed a similar pattern. In conclusion, Eker rats had significantly elevated cerebral O 2 consumption and blood flow, but this was not affected by GABA receptor blockade. This suggested a reduced activity of the GABA A receptor in the brains of Eker rats. This may have important implications in the treatment of autism.