Multiscale chemogenetic dissection of fronto-temporal top-down regulation for object memory in primates

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Primate Brain Research

Background:

• Visual object memory relies on the anterior temporal cortex in primates.
• The large-scale network and neuron-level top-down regulation for object memory remain unclear.

Purpose of the Study:

• Identify the orbitofrontal cortex's role in object memory.
• Investigate the neural mechanisms of top-down regulation in the ventral fronto-temporal network.

Main Methods:

• Whole-brain functional imaging during rest and a short-term object memory task in male macaques.
• Focal chemogenetic silencing of the orbitofrontal cortex.
• Imaging-guided neuronal recordings in the anterior temporal cortex.

Main Results:

• Orbitofrontal silencing downregulated orbitofrontal and anterior temporal activity, impairing memory but not perception.
• Orbitofrontal input enhanced stimulus-selective mnemonic signals in anterior temporal neurons.
• Neural activity differences correlated with memory performance, indicating behavioral relevance.

Conclusions:

• The orbitofrontal cortex is crucial for primate object memory.
• Top-down regulation from the orbitofrontal cortex modulates anterior temporal function for memory.
• This study provides a multiscale understanding of the ventral fronto-temporal network in object memory.