Effects of tactile stimulation on barrel cortex receptive fields in female rats

Experience-dependent plasticity plays a critical role in shaping neural circuits during early postnatal development. The barrel cortex is the primary somatosensory region responsible for processing whisker-derived tactile information in rodents, with each barrel representing a discrete anatomical and functional correlate of a single whisker. While tactile stimulation (TS) has been shown to influence sensory processing, its effects on female rats remain unexplored. The present study investigated the impact of TS on receptive field properties of barrel cortex neurons in female Wistar rats. Animals were divided into two groups: control (CTL) and TS. Neural responses to principal whisker (PW) and adjacent whisker (AW) deflections were recorded, and ON and OFF responses (excitatory responses evoked at stimulus onset and offset; PW or AW or PW-AW) as well as response latencies and PW/AW ratio were analyzed to assess changes in receptive field organization and sensory processing. Our results demonstrated that TS significantly increased ON and OFF response magnitudes in both PW and AW displacements during post-stimulation time windows. Additionally, TS significantly reduced response latencies across all conditions, suggesting enhanced temporal precision of sensory responses. Notably, the PW/AW ratio was significantly decreased in the TS group, indicating altered center-surround receptive field organization. Spontaneous activity and cross-whisker suppression ratios remained unchanged. These findings demonstrate that tactile stimulation enhances excitatory responses in the barrel cortex of female rats, providing novel insights into the mechanisms of sensory plasticity.