and Moser, 1998). Previous studies demonstrated that the
numeric working memory could be modulated by dopamine,
norepinephrine and other main neurotransmitters (Goldman-
Rakic et al., 2000; Arnsten and Robbins, 2002) and during
spatial memory task, both acetylcholine and serotonin in hippocampus
were simultaneously activated (Stancampiano et al.,
1999). Therefore, the acute effect of Centella asiatica on the
numeric memory and spatial memory might partly occur via the
modulation of dopamine and norepinephrine in prefrontal cortex
together with the modulation of acetylcholine and serotonin
in hippocampus. However, the possible underlying mechanisms
for acute effect of Centella asiatica on the numeric