Visual Neuroscience



Gender-specific modulation of short-term neuroplasticity in the visual cortex induced by transcranial direct current stimulation


LEILA  CHAIEB  a1 c1 , ANDREA  ANTAL  a1 and WALTER  PAULUS  a1
a1 Department of Clinical Neurophysiology, Georg-August University, Göttingen, Germany

Article author query
chaieb l   [Google Scholar] 
antal a   [Google Scholar] 
paulus w   [Google Scholar] 
 

Abstract

Transcranial direct current stimulation (tDCS) is a non-invasive method of modulating levels of cortical excitability. In this study, data gathered over a number of previously conducted experiments before and after tDCS, has been re-analyzed to investigate correlations between sex differences with respect to neuroplastic effects. Visual evoked potentials (VEPs), phosphene thresholds (PTs), and contrast sensitivity measurements (CSs) are used as indicators of the excitability of the primary visual cortex. The data revealed that cathodally induced excitability effects 10 min post stimulation with tDCS, showed no significant difference between genders. However, stimulation in the anodal direction revealed sex-specific effects: in women, anodal stimulation heightened cortical excitability significantly when compared to the age-matched male subject group. There was no significant difference between male and female subjects immediately after stimulation. These results indicate that sex differences exist within the visual cortex of humans, and may be subject to the influences of modulatory neurotransmitters or gonadal hormones which mirror short-term neuroplastic effects.

(Received August 30 2007)
(Accepted December 14 2007)


Key Words: Visual cortex; Neuroplasticity; tDCS; Gender-effects.

Correspondence:
c1 Address correspondence and reprint requests to: Leila Chaieb, Department of Clinical Neurophysiology, Georg-August University, Robert-Koch-Str. 40, 37075 Göttingen, Germany. E-mail: leilachaieb@med.uni-goettingen.de