Regulation of complexin 1 and complexin 2 in the developing human prefrontal cortex

Area of Science:

• Neuroscience
• Developmental Biology
• Synaptic Plasticity

Background:

• Complexins (CX1 and CX2) are key presynaptic proteins regulating neurotransmitter release.
• CX1 and CX2 serve as markers for excitatory and inhibitory synapses, respectively.
• Understanding synaptic development in the human prefrontal cortex (PFC) is crucial for cognitive function.

Purpose of the Study:

• To investigate the developmental trajectory of inhibitory and excitatory synapses in the human PFC.
• To examine the expression patterns of CX1 and CX2 during human brain development.

Main Methods:

• Western blotting was used to quantify CX1 and CX2 protein levels.
• Postmortem dorsolateral prefrontal cortex (DLPFC) samples from 42 individuals (18 weeks gestation to 25 years) were analyzed.
• Samples were grouped by age: fetal, infant, child, adolescent, and young adult.

Main Results:

• CX1 levels increased progressively throughout development, from fetal to young adult stages.
• CX2 levels increased from fetal to childhood and then plateaued.
• The CX2/CX1 ratio, indicative of inhibitory to excitatory synapse balance, was higher in fetal and infant groups compared to young adults.

Conclusions:

• Complexin expression and synaptic maturation increase during human DLPFC development.
• The balance of synaptic influence shifts towards inhibition relative to excitation during development in this brain region.
• These findings provide insights into the developmental neurobiology of synaptic function in the human PFC.