Mechanism of seizure-induced retrograde amnesia

Extrahippocampal Seizure and Memory Circuits Overlap

“…We selected 60 min because c-Fos mRNA expression peaks during that time ( Dabrowska et al, 2019 ). Previous studies find CA1 pyramidal neuron activation during this spatial memory task ( Naik et al, 2021 ). Here, we tested the activation of neurons in the structures outside of the CA1 and extrahippocampal systems that receive projections from the CA1 ( Fig.…”

“…1 G , p = 0.019). The CA1 pyramidal neuronal recruitment follows a similar trend across training sessions ( Naik et al, 2021 ).…”

“…On the second day of training, mice acquired the rewarded alteration memory because they demonstrated improved performance on the following and subsequent days ( Fig. 1 A ; Naik et al, 2021 ). Therefore, memory encoding occurred on day 2, and memory retrieval occurred on day 3.…”

“…We food-deprived mice to no less than 80% of their beginning body weight a week before to motivate them for the reward. After a week of food restriction and familiarization with sweetened milk, we trained mice in a delayed discrete trial rewarded alternation task for 5 d ( Naik et al, 2021 ). Days 1 and 2 served as a training session wherein no delay was introduced between sample and choice runs; however, on day 3 and afterward, a delay of 20 s was introduced between sample and choice trials.…”

“…We used GluA1 knock-out (KO) mice crossed with TRAP2 mice to confirm that labeled activated neurons were specific to spatial memory and not just locomotion or spatial navigation. A seizure shortly after a mouse has learned to alternate for a reward on the T-maze degraded performance the following day ( Naik et al, 2021 ). We tested whether seizure-activated neuronal ensembles overlapped spatial memory-activated neurons by performing TRAP2 and ARC dual-labeling.…”