Perineuronal nets play a role in regulating striatal function in the mouse

Area of Science:

• Neuroscience
• Developmental Biology
• Motor Control

Background:

• The striatum, a key basal ganglia nucleus, is crucial for motor control and learning.
• Perineuronal nets (PNNs), composed of chondroitin-sulfate proteoglycans (CSPGs), develop in the mouse striatum during early postnatal weeks.
• This developmental period coincides with significant motor system maturation, including gait acquisition.

Purpose of the Study:

• To identify cells ensheathed by PNNs in the striatum.
• To map the topographical distribution of striatal PNNs.
• To investigate the functional role of PNNs in striatal-dependent behaviors like ambulation and spatial learning.

Main Methods:

• Immunohistochemical analysis to identify PNN-associated cells, specifically parvalbumin-positive (PV+) interneurons.
• Enzymatic digestion of PNNs in the mouse striatum.
• Behavioral assessments including gait analysis and the Morris water maze.

Main Results:

• PNNs are more abundant in caudal striatal regions.
• A significant proportion of PNNs (41%) surround parvalbumin-positive (PV+) interneurons, with 51% of PV+ cells being ensheathed.
• Enzymatic digestion of striatal PNNs increased hind limb gait variability and improved spatial learning acquisition in the Morris water maze.

Conclusions:

• Perineuronal nets in the striatum are associated with specific neuronal populations, particularly PV+ interneurons.
• Striatal PNNs play a critical role in regulating motor function and spatial learning.
• Modulating PNNs offers a potential avenue for understanding and influencing striatal circuit function.