Vaibhav P Pai

Vaibhav P. Pai worked on membrane voltage and body plan in Xenopus embryos. Pai is credited with showing that voltage states can induce ectopic eyes in the gut¹. Pai also studied how HCN channels affect left-right organ placement²³, and how channel misexpression can repair nicotine-induced brain defects⁴⁶.

Field: researcher
In the library: 6 works, named in 12 passages elsewhere
Facts from: Wikidata · ORCID

Voltage and ectopic eyes

A 2012 study by Pai and colleagues is cited by later authors for one result. Changing cell voltage states induced eye formation in body areas such as the gut, where the master eye regulator Pax6 cannot induce eyes¹. Later reviews use this as an example of a simple bioelectric state triggering a complex organ.

Left-right laterality

In a 2017 paper, Pai and colleagues tested HCN4 channel function in left-right patterning. They found that HCN4 activity helps determine heart and visceral organ laterality. The activity must act very early, during cleavage stages². They also asked whether HCN4 inhibition acts by disturbing the sidedness of the Nodal, Lefty and Pitx2 cascade, which most known early asymmetry mechanisms feed into³.

Rescue of brain defects

Pai and colleagues built a Xenopus model of nicotine teratogenesis. They paired it with a computational model of voltage regulation⁴. Voltage dye images were calibrated against whole-cell recordings of neural plate and ectodermal cells⁵. In the 2020 paper, HCN2 expressed in neural tissue significantly counteracted the effect of nicotine on brain patterning⁶. Later reviews group this work with rescue of Notch-mutant brain defects by voltage control⁷.

SourcesEach quotation was checked word for word against the passage it opens.

inducing eye formation in ectopic body areas, such as the gut, where the master eye regulator Pax6 cannot induce eyes (Pai et al., 2012)Pietak A, Levin M, 2016 · Exploring Instructive Physiological Signaling with the Bioelectric Tissue… · open at passage 4
We conclude that HCN4 channel activity is involved in determining heart and visceral organ laterality; moreover, its activity must occur very early during cleavage stagesPai VP, Willocq V, Pitcairn EJ, Lemire JM, Paré JF, Shi NQ…, 2017 · HCN4 ion channel function is required for early events that regulate anatomical… · open at passage 12
Thus, we asked if HCN4 channel inhibition induces randomization by perturbing the normally consistent sidedness of this transcriptional cascade.Pai VP, Willocq V, Pitcairn EJ, Lemire JM, Paré JF, Shi NQ…, 2017 · HCN4 ion channel function is required for early events that regulate anatomical… · open at passage 14
Here, we establish an amphibian model for nicotine teratogenesis, and exploit the Xenopus embryo as proof-of-principle of how computational models of physiological regulatory eventsPai VP, Pietak A, Willocq V, Ye B, Shi NQ, Levin M, 2018 · HCN2 Rescues brain defects by enforcing endogenous voltage pre-patterns · open at passage 4
Whole-cell electrophysiological recordings of Vmem from neural plate cells and flanking ectodermal cells were used as calibration points for the voltage reporter dye imagesPai VP, Pietak A, Willocq V, Ye B, Shi NQ, Levin M, 2018 · HCN2 Rescues brain defects by enforcing endogenous voltage pre-patterns · open at passage 20
Thus, overexpression of HCN2-WT channels in neural tissue is able to significantly counteract the teratogenic effects of nicotine exposure on brain patterning.Pai VP, Cervera J, Mafe S, Willocq V, Lederer EK, Levin M, 2020 · HCN2 Channel-Induced Rescue of Brain Teratogenesis via Local and Long-Range… · open at passage 20
Severe brain defects in the frog model, induced by chemical teratogens or mutation of a critical neurogenesis gene (Notch), have been rescued by reinforcing appropriate bioelectrical signalingLevin M, 2023 · Bioelectric networks: the cognitive glue enabling evolutionary scaling from… · open at passage 51