Reply to Ahissar et al.

reply: We are grateful for the comments by Ahissar et al. on our recent manuscript (Masri et al. 2008) and for the opportunity to respond to these comments. Our manuscript focused on testing the hypothesis—formulated by Ahissar and collaborators—that the paralemniscal pathway in the rat's vibrissae system functions as a phase-locked loop (PLL) (Ahissar et al. 2000; Sosnik et al. 2001). We emphasize that we do not question the validity of their experimental results or of their analyses. Rather, our goal was to critically test their hypothesis that this sensory system makes use of a PLL mechanism. Two critical predictions emerge from this hypothesis: 1) response latency of neurons in the posteromedial thalamic nucleus (POm) correlates positively with whisking frequency and 2) response duration of these neurons correlates negatively with whisking frequency. In our manuscript we demonstrated that neither of these predictions holds true.