Efficient cortical coding of 3D posture in freely behaving rats.

Area of Science:

• Neuroscience
• Motor Control
• Computational Neuroscience

Background:

• Animals dynamically adjust body posture for diverse behaviors.
• Neural underpinnings of posture control are not fully understood.
• Posterior parietal cortex (PPC) and frontal motor cortex (M2) are key for movement and navigation.

Purpose of the Study:

• To investigate neural signals controlling body posture in freely moving animals.
• To determine the role of PPC and M2 in representing and decoding posture.
• To explore the topographical organization and coding strategies for posture in these brain regions.

Main Methods:

• Three-dimensional tracking of freely foraging rats.
• Simultaneous electrophysiological recordings from PPC and M2.
• Analysis of neural tuning to head, neck, and back posture.
• Decoding of ongoing behavior from neural activity.

Main Results:

• Both PPC and M2 exhibit strong neural tuning to head, neck, and back posture.
• Posture representations are topographically organized within PPC and M2.
• Neurons preferentially represent less frequent postures, suggesting efficient coding.
• Neural activity in PPC tends to precede activity in M2.
• Population codes in PPC and M2 are spatially organized and energetically efficient.

Conclusions:

• PPC and M2 play a crucial role in representing body posture.
• These brain regions utilize spatially organized, efficient population codes for posture representation.
• Neural dynamics suggest a sequential processing of postural information from PPC to M2.