Piracetam's improving effects on the fluidity of aged synaptosomal membranes could explain the beneficial effects of piracetam on age-related deficits on several mechanisms of signal transduction such as receptor density and function, and transmitter release, since these mechanisms are disturbed in the aging brain probably due to a decrease of membrane fluidity (Stoll et al., 1992; Viana et al., 1992; Cohen and Muller, 1993; Scheuer et al., 1999). On the other hand, initial evidence that piracetam's beneficial effects on the fluidity of aged mitochondrial membranes could contribute to its therapeutic efficacy originated from observations that piracetam could improve glucose uptake and utilization as well as ATP production (Domanska-Janik and Zaleska, 1977; Heiss et al., 1988; Dormehl et al., 1999; Keil et al., 2006). These effects led to the term “metabolic enhancer,” sometimes used to characterize piracetam and related nootropics (Malik et al., 2007). However, the mechanism of these effects and its possible relationship to mitochondrial function remained obscure.