CA2 neuronal activity controls hippocampal low gamma and ripple oscillations

GM Alexander, LY Brown, S Farris, D Lustberg… - Elife, 2018 - elifesciences.org
GM Alexander, LY Brown, S Farris, D Lustberg, C Pantazis, B Gloss, NW Plummer, P Jensen…
Elife, 2018elifesciences.org
Hippocampal oscillations arise from coordinated activity among distinct populations of
neurons and are associated with cognitive functions. Much progress has been made toward
identifying the contribution of specific neuronal populations in hippocampal oscillations, but
less is known about the role of hippocampal area CA2, which is thought to support social
memory. Furthermore, the little evidence on the role of CA2 in oscillations has yielded
conflicting conclusions. Therefore, we sought to identify the contribution of CA2 to …
Hippocampal oscillations arise from coordinated activity among distinct populations of neurons and are associated with cognitive functions. Much progress has been made toward identifying the contribution of specific neuronal populations in hippocampal oscillations, but less is known about the role of hippocampal area CA2, which is thought to support social memory. Furthermore, the little evidence on the role of CA2 in oscillations has yielded conflicting conclusions. Therefore, we sought to identify the contribution of CA2 to oscillations using a controlled experimental system. We used excitatory and inhibitory DREADDs to manipulate CA2 neuronal activity and studied resulting hippocampal-prefrontal cortical network oscillations. We found that modification of CA2 activity bidirectionally regulated hippocampal and prefrontal cortical low-gamma oscillations and inversely modulated hippocampal ripple oscillations in mice. These findings support a role for CA2 in low-gamma generation and ripple modulation within the hippocampus and underscore the importance of CA2 in extrahippocampal oscillations.
eLife