Island cells control temporal association memory.
Episodic memory requires associations of temporally discontiguous events. In the entorhinal-hippocampal network, temporal associations are driven by a direct pathway from layer III of the medial entorhinal cortex (MECIII) to the hippocampal CA1 region. However, the identification of neural circuits that regulate this association has remained unknown. In layer II of entorhinal cortex (ECII), we report clusters of excitatory neurons called island cells, which appear in a curvilinear matrix of bulblike structures, directly project to CA1, and activate interneurons that target the distal dendrites of CA1 pyramidal neurons. Island cells suppress the excitatory MECIII input through the feed-forward inhibition to control the strength and duration of temporal association in trace fear memory. Together, the two EC inputs compose a control circuit for temporal association memory.
RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
Takashi
T
Kitamura
Michele
M
Pignatelli
Junghyup
J
Suh
Keigo
K
Kohara
Atsushi
A
Yoshiki
Kuniya
K
Abe
Susumu
S
Tonegawa
D000818:Animals; D001244:Association; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D018728:Entorhinal Cortex / Q000166:cytology / Q000502:physiology*; D059330:GABAergic Neurons / Q000502:physiology; D007395:Interneurons / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics; D061212:Memory, Episodic; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009415:Nerve Net; D009474:Neurons / Q000502:physiology*
D008565:Membrane Proteins; C114987:wolframin protein