title: Interrelation between cerebral energy metabolism and behaviour in a rat model of permanent brain vessel occlusion.
abstract: The present study investigates the interrelation between cerebral energy metabolism and memory capacities after acute and permanent occlusions of carotid and vertebral arteries in adult Wistar rats (n=60). Tissue ATP, phosphocreatine, ADP, AMP and adenosine concentrations were determined in rat brain by high-pressure liquid chromatography (HPLC) analysis. Lactate and pyruvate were measured spectrophotometrically. Rats underwent psychometric testing by means of a holeboard test, closed field activity, and passive avoidance behaviour. Acute cerebral ischaemia was associated with a substantial deficit in energy load (-50%). Cortical adenosine and lactate exhibited a 7- and a 10-fold increase, respectively, in concentration. After 2 weeks of four-vessel occlusion, cortical ATP and phosphocreatine showed a partial enhancement in their concentrations if compared with acute ischaemia. Consequently, energy load (micromol/g) increased from 0.59 to 1.42 in cerebral cortex and from 0.58 to 1.14 in hippocampus under conditions of acute and permanent ischaemia, respectively. While lactate was normalized, adenosine showed a 2-fold increase in its cortical concentration. All animals improved their abilities in learning, memory and cognition after a 7-day training period. Acute vessel occlusion severely decreased working memory (WM), reference memory (RM) and locomotor activity. Simultaneously, the passive avoidance test showed a significant reduction in latency time from 247+/-85 s (sham) to 145+/-132 s. The partial improvement in brain energy state was accompanied by a relative improvement in WM and RM, although both memory capacities remained significantly lower than in controls. The data of the present study demonstrate a linear relationship between cerebral energy metabolism and brain memory capacities after acute and permanent vessel occlusions in rats.
authors.affiliation: Clinic of Anesthesiology, University of Heidelberg, Im Neuenheimer Feld 110, D-69120, Heidelberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Plaschke
authors.forename: S W
authors.initials: SW
authors.lastname: Yun
authors.forename: E
authors.initials: E
authors.lastname: Martin
authors.forename: S
authors.initials: S
authors.lastname: Hoyer
authors.forename: H J
authors.initials: HJ
authors.lastname: Bardenheuer
mesh_terms: D000818:Animals; D001157:Arterial Occlusive Diseases / Q000378:metabolism* / Q000523:psychology; D001362:Avoidance Learning / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000378:metabolism*; D002545:Brain Ischemia / Q000378:metabolism* / Q000523:psychology; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000502:physiology*; D016014:Linear Models; D008297:Male; D008568:Memory / Q000502:physiology*; D011594:Psychometrics; D051381:Rats; D017208:Rats, Wistar