Hippocampal infusions of pyruvate reverse the memory-impairing effects of septal muscimol infusions.
Hippocampal infusions of glucose reverse memory deficits in spontaneous alternation and in a continuous multiple trial inhibitory avoidance task. The current experiments tested whether glucose metabolism may participate in these effects of glucose. Specifically, these experiments determined whether the glycolytic metabolite pyruvate would mimic these effects of glucose. Male Sprague-Dawley rats were given septal infusions of vehicle or the gamma-aminobutyric acid (GABA) receptor agonist muscimol (0.15 nmol for spontaneous alternation or 5 nmol for continuous multiple trial inhibitory avoidance) combined with hippocampal infusions of vehicle or pyruvate (200 nmol) 15 min prior to assessing spontaneous alternation or training in a continuous multiple trial inhibitory avoidance task. The infusions of muscimol decreased percent alternation scores and continuous multiple trial inhibitory avoidance retention latencies tested 48 h after training. More importantly, hippocampal infusions of pyruvate reversed the deficits produced by septal infusions of muscimol on both tasks. These findings show for the first time that hippocampal infusions of pyruvate influence memory and suggest that glucose may affect memory via glycolytic metabolism.
Krebs
Desiree L
DL
Department of Psychology and Center for Behavioral Neuroscience, Georgia State University, P. O. Box 3966, Atlanta, Georgia 30302-3966, USA.
Parent
Marise B
MB
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D004597:Electroshock; D018755:GABA Agonists; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced / Q000517:prevention & control*; D008570:Memory, Short-Term / Q000187:drug effects; D009118:Muscimol; D019289:Pyruvic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012153:Retention, Psychology / Q000187:drug effects; D020665:Septum of Brain
D018755:GABA Agonists; D009118:Muscimol; D019289:Pyruvic Acid