Dravet syndrome (DS) is an early-onset epilepsy caused by loss-of-function mutations in the SCN1A gene, which encodes Nav1.1 channels that preferentially regulate activity of inhibitory neurons early in development. DS is associated with a high incidence of sudden unexpected death in epilepsy (SUDEP) by a mechanism that may involve respiratory failure. Evidence also shows that loss of Scn1a impaired activity of neurons in the retrotrapezoid nucleus (RTN) that regulate breathing in response to CO2/H+, suggesting breathing problems precede seizures and serve as a biomarker of SUDEP. Consistent with this, we showed that Scn1a+/– mice exhibited a blunted ventilatory response to CO2/H+ prior to overt seizure activity that worsened with disease progression. Later in development, some Scn1a+/– mice also showed a blunted ventilatory response to hypoxia. Importantly, the severity of respiratory problems correlated with mortality. We also found that pharmacological activation of Nav1.1 rescued activity deficits of RTN neurons in Scn1a+/– mice. We conclude that disordered breathing may be an early biomarker of SUDEP in DS, and at the cellular level, loss of Scn1a disrupts RTN neurons by mechanisms involving disinhibition and pharmacological activation of Nav1.1 to reestablish inhibitory control of RTN neurons rescues activity deficits.
Brenda M. Milla, Eliandra N. da Silva, Cleyton R. Sobrinho, Monica L. Strain, Daniel K. Mulkey
Usage data is cumulative from September 2025 through May 2026.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 2,223 | 129 |
| 672 | 44 | |
| Figure | 334 | 0 |
| Supplemental data | 173 | 6 |
| Citation downloads | 91 | 0 |
| Totals | 3,493 | 179 |
| Total Views | 3,672 | |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.