Dynamic Reorganization of Neuronal Activity Patterns in Parietal Cortex

Abstract

Summary Neuronal representations change as associations are learned between sensory stimuli and behavioral actions. However, it is poorly understood whether representations for learned associations stabilize in cortical association areas or continue to change following learning. We tracked the activity of posterior parietal cortex neurons for a month as mice stably performed a virtual-navigation task. The relationship between cells’ activity and task features was mostly stable on single days but underwent major reorganization over weeks. The neurons informative about task features (trial type and maze locations) changed across days. Despite changes in individual cells, the population activity had statistically similar properties each day and stable information for over a week. As mice learned additional associations, new activity patterns emerged in the neurons used for existing representations without greatly affecting the rate of change of these representations. We propose that dynamic neuronal activity patterns could balance plasticity for learning and stability for memory.

Feedback inhibition derived from the posterior parietal cortex regulates the neural properties of the mouse visual cortex

“…In this study, we analyzed the function of PPC and found that the area suppressed the activity of V1 constantly, was related to the neuronal properties of V1, but there are some points to be noted. First, the region of the PPC in this study was ~0.5 mm more medial than what other recent studies identified as the PPC (Driscoll, Pettit, Minderer, Chettih, & Harvey, ; Goard, Pho, Woodson, & Sur, ; Hwang, Dahlen, Mukundan, & Komiyama, ). It has been pointed out that the PPC is composed of two distinct areas (medial and lateral PPC) in rats (Reep & Corwin, ), so it is likely that these may be two functionally distinct areas in mice.…”

“…Second, in this study we used the artificial stimulus methods for the PPC activation. They may cause the synchronous firing pattern of the PPC which may be different from that in the physiological activation (Driscoll et al., ; Goard et al., ; Harvey, Coen, & Tank, ; Hwang et al., ), although they were able to reveal the PPC function latent under physiological conditions. And finally, the possibility could not be thoroughly ruled out that the incision we made between the PPC to V1 may impact communication between other medial areas and V1.…”

Architecture and organization of mouse posterior parietal cortex relative to extrastriate areas

“…Later work established their connection strengths and retinotopic response properties systematically and at larger scales (Andermann, Kerlin, Roumis, Glickfeld, & Reid, 2011;Garrett, Nauhaus, Marshel, & Callaway, 2014;Marshel, Garrett, Nauhaus, & Callaway, 2011;Wang & Burkhalter, 2007), and their projections to other cortical areas were also mapped (Wang et al, 2012). Since the dorsal cortical surface in rodents lacks gross anatomical landmarks, the pattern of responses in extrastriate areas have provided increasingly-used functional landmarks for locating higher visual (Garrett et al, 2014) and associative regions in the posterior cortex (Driscoll, Pettit, Minderer, Chettih, & Harvey, 2017;Olcese, Iurilli, & Medini, 2013). However, functional mapping of this kind is not feasible in the absence of a broadly expressed calcium indicator or intrinsic optical imaging, and the location of these areas relative to PPC had not been defined explicitly until now.…”

Three brain states in the hippocampus and cortex

“…To specify, episodic memory involves (a) single episodes encompassing longer periods of time (seconds to minutes and longer) (Ferbinteanu, Kennedy, & Shapiro, ; Shapiro, Kennedy, & Ferbinteanu, ; Smith & Mizumori, ), (b) knowledge of temporal relationships across episodes, and (c) retrieval of episodes long after initial storage. Although recent work has provided promising clues (Attardo, Fitzgerald, & Schnitzer, ; Cai et al, ; Driscoll, Pettit, Minderer, Chettih, & Harvey, ; Eichenbaum, ; Eichenbaum, ; Eichenbaum, ; Ezzyat & Davachi, ; Ferbinteanu & Shapiro, ; Frank, Stanley, & Brown, ; Hsieh, Gruber, Jenkins, & Ranganath, ; Karlsson & Frank, ; Kitamura et al, ; Ludvig, ; Mankin et al, ; Mankin et al, ; Manning, Polyn, Baltuch, Litt, & Kahana, ; Manns, Howard, & Eichenbaum, ; Murray et al, ; Ranganath & Hsieh, ; Rubin, Geva, Sheintuch, & Ziv, ; Runyan, Piasini, Panzeri, & Harvey, ; Suh, Rivest, Nakashiba, Tominaga, & Tonegawa, ; Ziv et al, ), the neural representation of events at longer timescales remains unclear. More knowledge and insight are needed.…”