Changes in Action Potential Properties in the Ferret Prefrontal Cortex During Adolescence

Area of Science:

• Neuroscience
• Animal Models
• Developmental Biology

Background:

• Ferrets, with their gyrencephalic brains, serve as valuable models for human brain development and disorders.
• There is a lack of consensus regarding the definition of adulthood in ferrets, with studies using varied age ranges.
• Adolescence is marked by physical and behavioral changes, but brain maturation, particularly in the prefrontal cortex (PFC), extends beyond puberty.

Purpose of the Study:

• To investigate the functional maturation of the ferret prefrontal cortex (PFC) as a marker for the transition from adolescence to adulthood.
• To determine the age at which the ferret PFC achieves functional maturity.

Main Methods:

• Whole-cell patch clamp recordings were performed on pyramidal neurons (PNs) in the prelimbic cortex of the ferret medial PFC.
• Electrophysiological properties were analyzed at three ages post-puberty: P120, P180, and P220.
• Injected current-firing curves and sag amplitude were measured to assess neuronal excitability.

Main Results:

• Neuronal excitability in the ferret PFC significantly changed between P120 and P220.
• An increased amount of current was required to elicit action potentials (APs) at P220 compared to P120.
• An increase in sag amplitude and a reduction in rheobase were observed, indicating altered neuronal properties.

Conclusions:

• The excitability of PNs in the ferret prelimbic cortex undergoes developmental changes after puberty.
• Functional maturation of the ferret PFC, as assessed by these electrophysiological markers, is not complete before P220.
• P220 represents a potential age marker for adulthood in ferrets, based on PFC functional maturity.