Introduction and objective:
Sevoflurane, a commonly used inhalation anaesthetic in paediatric procedures, has been associated with cognitive impairments, particularly affecting learning and memory. Despite its widespread use, the mechanisms underlying its neurocognitive effects remain unclear. The aim of the study is to investigate the impact of sevoflurane exposure at various developmental stages and dosages on learning and memory in pre-adolescent rats.

Material and methods:
Ninety male Wistar rat pups were randomly assigned to six groups: Control, Sham, S1 (single dose on postnatal day 7 [P7]), S2 (repeated doses on P7, P8, P9), S3 (single dose on P21), and S4 (repeated doses on P21, P22, P23). Morris Water Maze (MWM) Test was performed to LTP was recorded to assess synaptic plasticity., while Open Field Test (OFT) was utilized to assess locomotor activity and anxiety-like behaviours. Long-term potentiation (LTP) recordings were performed to assess synaptic plasticity.

Results:
Sevoflurane exposure impaired learning and memory, with deficits most pronounced in the early exposure (S2) and repeated-dose (S2 and S4) groups. In the MWM, S2 showed significantly prolonged escape latency and reduced target-quadrant time, indicating impaired spatial memory.OFT revealed decreased locomotor activity and increased anxiety-like behaviours in S2, suggesting greater neurocognitive impairment following early developmental exposure and repeated dosing. LTP recordings demonstrated reduced fEPSP slopes and population spike (PS) amplitudes, particularly in S2 and repeated-dose groups, further supporting impaired synaptic plasticity, learning, and memory.

Conclusions:
Early-stage and repeated-dose sevoflurane exposure disrupts learning, memory, and locomotor activity, highlighting the importance of timing and dosage in paediatric anaesthesia.