Behavior and Regional Cortical BOLD Signal Fluctuations Are Altered in Adult Rabbits After Neonatal Volatile...

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Cognitive Neuroscience

Background:

• Neonatal exposure to volatile anesthetics is linked to long-term learning and memory deficits.
• Underlying functional brain changes associated with these impairments are not well understood.

Purpose of the Study:

• To investigate the relationship between functional alterations in neuronal circuits and learning deficiency after early anesthesia exposure.
• To examine resting-state functional MRI (rsfMRI) connectivity in adolescent rabbits following neonatal anesthesia.

Main Methods:

• Adolescent rabbits exposed to isoflurane anesthesia neonatally were compared to controls.
• Resting-state functional MRI (rsfMRI) was used to measure connectivity and regional brain activity (ALFF, fALFF, ReHo).
• Animals were trained on a trace eyeblink classical conditioning (ECC) paradigm before and after imaging.

Main Results:

• Anesthesia-exposed rabbits showed significantly lower trace ECC learning rates.
• Higher Amplitude of Low-Frequency Fluctuations (ALFF) was observed in the primary and secondary somatosensory cortices of anesthesia-exposed rabbits.
• ALFF in these areas predicted learning performance, while long-range connectivity, fALFF, and ReHo remained unchanged.

Conclusions:

• Neonatal anesthesia exposure disrupts functional brain development, specifically increasing ALFF in the somatosensory cortex.
• This disruption, potentially involving excessive neuronal synchronization, may underlie observed cognitive deficits.
• Functional thalamocortical connectivity appears unaffected by early anesthesia exposure.