Researchers at Baylor College of Medicine have uncovered a previously unrecognized mechanism by which inherited calcium channel mutations disrupt early brain development and predispose children to epilepsy and related cognitive challenges. The findings, published in Neuron , shed new light on how subtle genetic changes can alter brain circuits long before seizures begin.
The study, conducted in the Blue Bird Circle Developmental Neurogenetic Laboratory at Baylor, focuses on mutations in P/Q-type calcium channels, critical regulators of neurotransmitter release in the brain. This mutation has been known to be associated with childhood epilepsy, but how it affects neural circuits in early development is not fully understood.
Using a mouse model to mimic childhood absence epilepsy, Samantha Thompson , graduate student, and Dr. Qing-Long Miao , assistant professor of neurology , both with Baylor, were able to trace how a single calcium channel mutation influences the genetic pathway.
Childhood absence epilepsy is characterized by abnormal cortical spike-wave discharges arising from thalamocortical circuits linking the thalamus and cortex, which regulate consciousness, attention and sensory processing.
“While loss-of-function mutations in P/Q-type calcium channels impair neurotransmitter release, we were surprised to find that they also increase thalamic excitability,” said Miao.
The team found that this mutation significantly increased the expression of two downstream proepileptic genes previously linked to absence epilepsy in children. Unexpectedly, the altered calcium channel also activated a major growth‑signaling pathway in the brain known as Wnt signaling, driving excessive proliferation of thalamic relay neurons – cells critical for regulating consciousness and sensory processing.
“Strikingly, this surge in neuronal growth began before birth, indicating that the disorder’s origins arise much earlier than the childhood onset of seizures would suggest,” said Thompson. “The findings highlight a prenatal developmental window of vulnerability that has been largely overlooked in epilepsy research.”
The authors suggest that the simultaneous dysregulation of two epilepsy‑related gene pathways may help explain why many children fail to respond to standard single‑agent antiseizure medications.
“These insights open the door to earlier diagnostics and more targeted therapies,” explained Dr. Jeffrey Noebels , director of the Blue Bird Circle Developmental Neurogenetic Laboratory. “Understanding how these pathways interact and pinpointing the correct target could transform how we treat the seizures and attention deficit in childhood epilepsy.”
“These findings reveal that inherited ion channel mutations don’t just affect electrical signaling – they also reshape the developmental trajectory of brain circuits,” said Noebels.
This discovery opens new avenues for earlier detection and the development of targeted therapies aimed at both neural excitability and developmental signaling pathways that could one day improve outcomes in children affected by epilepsy and related neurodevelopmental disorders.
Others who took part in the research include Anika Sonig, Development Neurogenetics Laboratory at Baylor. Please see the publication for all funding information.
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Neuron
Experimental study
Animals
Presynaptic P/Q calcium channel deficit promotes postsynaptic excitability remodeling and neurogenesis in developing thalamic circuitry
2-Apr-2026