Author(s): Alhaj HA, McAllister-Williams RH
Abstract: Background: The adrenal steroid dehydroepiandrosterone (DHEA) has been shown to improve memory performance and modulate the neural activity in rodents. Further, we have demonstrated beneficial effects of DHEA on long-term episodic memory performance in healthy humans. To further evaluate the effects of DHEA on human central nervous system, a study of auditory event-related potentials (ERPs) was conducted. Methods: In this double blind placebo-controlled crossover study, 24 healthy young men (aged between 18 and 34) took DHEA (300 mg/day) or placebo for one week. Following each treatment period, subjects participated in an auditory oddball paradigm, during which subjects heard high (frequent) and low (rare) tones and were instructed to count the rare tone silently. ERPs were recorded using 29 electrodes according to the 10-20 system. Results: DHEA treatment led to a significant increase in the amplitude of N1 component of the ERPs in the posterior electrode sites (p<0.05). The latency of the P3 component was decreased in the posterior and central sites (p<0.05), reflecting greater information updating in short-term memory. P3 amplitude was not affected after DHEA administration. Conclusions: A weeklong DHEA in healthy young men results in larger N1 component deflection, possibly reflecting a reduction in the threshold of the attention-switching mechanism of the neural generators of N1 (Naatanen, 1992). Further, DHEA led to acceleration in electrophysiological stimulus processing of short-term memory, as shown by decreased P3 component latency. These findings reflect a possible neuronal excitation and support the hypothesis that DHEA has a positive impact on neurocognitive processes.