Pannexin 1 Regulates Network Ensembles and Dendritic Spine Development in Cortical Neurons

Area of Science:

• Neuroscience
• Molecular Biology
• Developmental Biology

Background:

• Dendritic spines, crucial for excitatory synaptic input, undergo significant development in early postnatal life.
• The molecular regulators of dendritic spine proliferation and maturation during this period are not fully understood.
• Pannexin 1 (Panx1) has been implicated in neurite growth and synaptic plasticity.

Purpose of the Study:

• To investigate the role of pannexin 1 (Panx1) in regulating dendritic spine development and cortical network activity.
• To determine the impact of global Panx1 knockout (KO) on spontaneous cortical neuron activity and synapse maturation.

Main Methods:

• Calcium (Ca2+) imaging and in silico network analysis of spontaneous cortical neuron activity in Panx1 KO mice.
• Analysis of Panx1 protein levels and postsynaptic density proteins in postnatal cortical synaptosomes.
• Ex vivo and in vitro examination of pyramidal neuron dendritic spine density in Panx1 KO models.

Main Results:

• Panx1 knockout increased the number and size of spontaneous co-active cortical neuron network ensembles.
• Cortical synaptosome protein levels of Panx1 decreased significantly between postnatal weeks 2 and 4.
• Panx1 KO mice exhibited enrichment of excitatory postsynaptic density proteins and increased dendritic spine densities.

Conclusions:

• Pannexin 1 (Panx1) negatively regulates the development of dendritic spines in the mouse cortex.
• Panx1 plays a critical role in controlling synapse proliferation and maturation during early postnatal development.
• These findings highlight Panx1 as a key molecular player in establishing cortical excitatory circuitry.