Alteration of Neuregulin 1/Erbb4 in Absence Epilepsy: Regulatory Effect on TRPV1 Expression

The footprint of Neuregulin 1 (NRG1) / ERbB4 in the pathophysiology of some neurological disorders and TRPV1 regulation has been indicated. The alterations of NRG1 and ErbB4 as well as TRPV1 signaling pathway was investigated during development of absence epilepsy in the genetic animal model of absence epilepsy. Male WAG/Rij and Wistar rats were divided into four experimental groups of 2 and 6 months of age. The protein level of NRG1, ERbB4 and TRPV1 were measured in the somatosensory cortex and hippocampus. The cortical protein level of NRG1 and ErbB4 in the 6-month-old WAG/Rij rats was lower than Wistar rats. Protein level of TRPV1 was lower in 2- and 6-month-old WAG/Rij rats compared to age-matched Wistar rats. Hippocampal protein level of NRG1 in 6-month-old WAG/Rij rats was lower than 2-month-old WAG/Rij rats. Low level of ErbB4 protein in 2-month-old and high level in 6-month-old WAG/Rij rats was shown compared to Wistar rats. Protein level of TRPV1 was lower in the 2-month-old and higher in 6-month- old WAG/Rij rats compared to age-matched Wistar rats. Furthermore, high correlation between NRG1/ERbB4 and TRPV1 expressions in the cortex and hippocampus was indicated. The expression of NRG1/ERbB4 and TRPV1 followed a similar pattern during life span of Wistar and WAG/Rij rats.Our findings indicated the potential role of NRG1/ErbB4 pathway as well as TRPV1 in the pathogenesis of absence epilepsy. The regulatory effect of ERbB4 receptor on the TRPV1 expression has been suggested following by the similarity pattern of expression.