HCN2 promotes neurodevelopmental and synaptic function repair through the CaMKII/CREB pathway to alleviate general anesthesia-induced cognitive impairment

Abstract

Repeated exposure to gestational general anesthesia during pregnancy has been associated with neurodevelopmental damage and cognitive and social dysfunction in offspring. This study investigates the underlying mechanisms and therapeutic strategies for mitigating these effects. Behavioral tests revealed significant impairments in cognitive, social, and spatial learning abilities in the offspring of general anesthesia-treated mice, alongside delayed eye-opening, reduced body weight, and neuronal damage. Mechanistic analyses showed that general anesthesia exposure disrupted ionic homeostasis, reduced hyperpolarization-activated cyclic nucleotide-gated channel (HCN) expression, and suppressed the calcium/calmodulin-dependent protein kinase II (CaMKII)/cAMP-response element-binding (CREB) protein signaling pathway, leading to synaptic dysfunction and impaired neuronal activity. Therapeutic strategies using adeno-associated virus (AAV)-mediated HCN2 overexpression restored HCN2 expression, improved ionic homeostasis, and reactivated the CaMKII/CREB signaling pathway, significantly ameliorating cognitive, social, and synaptic deficits. In vitro, lentivirus-HCN2 overexpression rescued disrupted sodium and potassium levels, synaptic protein expression (synaptophysin and brain-derived neurotrophic factor), and protein kinase A activity. However, these improvements were attenuated when CaMKII or CREB functions were inhibited, highlighting their critical roles in HCN2-mediated neural regulation. In vivo, AAV-HCN2 and AAV-CREB therapies improved neuronal activity, synaptic integrity, and behavioral outcomes in general anesthesia-exposed offspring, while CaMKII inhibition exacerbated developmental and behavioral abnormalities. These findings demonstrate that HCN2 improves neural function, synaptic plasticity, and behavior through the CaMKII/CREB signaling pathway. This study provides new insights into potential therapeutic strategies for neurodevelopmental damage caused by repeated general anesthesia exposure.