Neonatal Tactile Stimulation Modulates Dendritic Spine Densities in Somatosensory Cortex of Adult WAG/Rij rats
Abstract Background In previous studies, it has been shown that in early developmental period, the high level of tactile stimulations prevent absence epilepsy development and comorbid depression in Wistar-Albino-Glaxo from Rijswijk (WAG/Rij) rats with absence epilepsy. The aim of our study is to examine the effects of neonatal tactile stimulatons on the brain structures that previously defined as the focus of epilepsy in the rat brain with genetic absence epilepsy. Results In the present research, morphology and density of dendritic spines were analyzed in the somatosensory cortex (SoCx) in WAG/Rij rats with absence epilepsy, sensory experienced WAG/Rij rats (tactile-stimulated and maternal separated) and healthy Wistar (non-epileptic) rats. To achieve this, a Golgi-Cox method was used. Dendritic spine number in layer V of the SoCx has been detected significantly higher in adult WAG/Rij rats at post natal day 150 in comparison to non-epileptic adult control Wistar rats (p < 0,001). Moreover, quantitative analyses of dendrite structure in adult WAG/Rij rats showed a decrease in dendrite spine density of pyramidal neurons of SoCx which occurred in early neonatal exposure to maternal separation (MS) and tactile stimulation (TS) (p < 0,001). Conclusions Our findings provide the first evidence that tactile stimulations during the early postnatal period have a long-term impact on dendrite structure in WAG/Rij rat’s brain and suggest a reduction in dendrite spine density is linked to absence seizure reduction.