Neural Network of Episodic Memory ─ An Insight from Thalamic Amnesia

Abstract

  The thalamus and medial temporal lobe are anatomically interconnected and work as an integrative functional unit for episodic memory. There are two distinct memory-related thalamo-medial temporal circuits: the first is the mammillary body-anterior thalamic nuclei-hippocampus circuit (Papez circuit) and the other is the rhinal cortex-mediodorsal thalamic nuclei-prefrontal cortex circuit. Recent rodent neurophysiological studies suggest that the mammillary body-anterior thalamic nuclei-hippocampus circuit plays a central role in integrating information about space, objects and action that are generated thorough subjective experience into individual mnemonic events. The rhinal cortex-mediodorsal thalamic nuclei-prefrontal cortex circuit are hypothesized to represent the relationship, or context, among mnemonic events that are formed through previous learning.