Lactate concentration, latency scores, n and detailed statistic are reported in Table S2. (A) Dorsal hippocampal extracellular lactate in freely moving rats infused with either vehicle or DAB. Baseline was collected for 20 min before training (0 min, ↑) and continued for 50 min. Training resulted in a significant increase in lactate levels compared to baseline (* p < 0.05) that was completely blocked by DAB (# p < 0.05).
Data are expressed as % of baseline ± SEM (mean of the first 2 samples set 100%). See also Figure S2.
(B-D) Acquisition (Acq) and retention are expressed as mean latency ± SEM (in seconds, sec).
(B and C) Hippocampal injection of DAB or vehicle in combination with 10 nmol (B, n = 7/group), 100 nmol L-lactate (C, n = 12/group) or vehicle were performed 15 min before training and memory was tested at 24 hr. 100 nmol but not 10 nmol of L-lactate rescued the memory impairment by DAB (Test 1). The effect persisted at 7 days after training (Test 2).
(D) Hippocampal injections of D-lactate 15 min before training disrupted long-term memory (n=7-8/group). * p < 0.05.