Sleep and Movement Differentiates Actions of Two Types of Somatostatin-Expressing GABAergic Interneuron in Rat Hippocampus

Abstract

In the original article, there was an error in the two-sample Kolmogorov-Smirnov statistical testing of firing rate changes. The corrected p values changed the evaluation of individual cells under certain behavioral and network states but do not change the conclusions of the paper for the overall population of a given cell type. The legend to Figure 5 (F and G) should say that the measured distribution of the O-LM cell was similar to the median (black) of the surrogate set (p = 0.9, during sleep; p = 0.4, during wakefulness; two-sample KS tests), the legend to Figure S4 should say that three O-LM cells (B) changed their firing rates significantly during sleep SWRs (two-sample KS-tests, n = 3 cells in total, p < 0.05, for all cells) and for cells LK06ah and LK13k in the awake condition, the measured rates were similar to those expected from the surrogate sets, whereas, the rate of ZsB43d was lower than expected (two-sample KS-tests, LK06ah, p = 0.2; LK13k, p = 0.1; ZsB43d, p < 0.05), and the last paragraph of the Results section should say that during wakefulness, the firing rate during SWRs was significantly lower for one O-LM cell and higher for the other three cells than that expected (CDFs p < 0.05 for n = 4 cells; Figures 5G and S4B and Table 2). The authors regret the error and any confusion this may have caused.

Inhibitory microcircuit modules in hippocampal learning

“…For each theta cycle inhibition shifted from axon initial segment to soma, on to proximal dendrites (bistratified SOM) and finally distal dendrites (OLM SOM) of pyramidal neurons in CA1. This pattern of shifting inhibition might reflect organization of encoding (highest at raising phase) and retrieval (highest at descending phase and trough) [44,45]. Furthermore, recruitment of OLM SOM neurons was strongest during free movement and reduced during SWRs, whereas recruitment of bistratified SOM neurons was highest during slow-wave sleep.…”

“…These studies have focused on hippocampal network activity patterns such as theta oscillations related to spatial navigation [41 ,42], gamma oscillations related to information binding and transmission [43 ], and SWR related to compressed replay of neuronal sequences during quiet wakefulness and slow-wave sleep [44]. A so-called hippocampal chronocycle has been suggested to orchestrate alternate functions of encoding and retrieval [45] through segregation at the ascending and peak phase of theta (acquisition) and at the descending and trough of theta (retrieval) [42,44]. In parallel, the EC input to CA1 is most active near the peak of theta, whereas the trough is characterized by waning EC input, rising CA3 input, and strongest LTP induction.…”

“…Furthermore, SOM neurons controlled pyramidal neuron bursting activity but not theta phase locking, whereas PV neuron silencing did not affect firing rates but shifted firing towards the trough of theta [41 ,46]. A study from Somogyi et al investigated how inhibition is recruited during theta and sleep-related SWR activities [44]. For each theta cycle inhibition shifted from axon initial segment to soma, on to proximal dendrites (bistratified SOM) and finally distal dendrites (OLM SOM) of pyramidal neurons in CA1.…”

“…Furthermore, recruitment of OLM SOM neurons was strongest during free movement and reduced during SWRs, whereas recruitment of bistratified SOM neurons was highest during slow-wave sleep. The authors proposed that higher activity at distal dendrites during the rise of theta might contribute to selecting active neurons over inactive ones at the through of theta [44].…”

GABAergic‐astrocyte signaling: A refinement of inhibitory brain networks

“…The exceptional properties of SST-driven astrocyte signaling, with high sensitivity to synaptic GABA and enhanced Ca 2+ signaling compared to PV interneurons, were mediated by the release of neuropeptide somatostatin. SST (but not PV) cells co-released neuropeptide somatostatin with GABA after intense activation (Katona et al, 2014;Mariotti et al, 2018). In addition, astrocytes displayed differential Ca 2+ plasticity after successive episodes of PV and SST interneuron activity (Mariotti et al, 2018).…”