Highlights d Phospho-tau is accumulated in DG GABAergic interneurons of AD patients and mice d Interneuron overexpressing human tau impairs adult hippocampal neurogenesis d Tau accumulation reduces GABA, disinhibits local circuits, and promotes astrogliosis d THIP, a d-GABA A R agonist, improves neurogenesis and cognition in AD mice

Highlights d Ventral hippocampal CA1-infralimbic cortex (vCA1-IL) connectivity is involved in pain d Persistent spontaneous pain in rats with inflammation disrupts vCA1-IL connectivity d Activating vCA1-IL alleviates spontaneous pain and promotes overall pain recovery d BDNF expression correlates with behavior and activity changes in spontaneous pain

Gamma-band oscillations (GBOs) elicited by transient nociceptive stimuli are one of the most promising biomarkers of pain across species. Still, whether these GBOs reflect stimulus encoding in the primary somatosensory cortex (S1) or nocifensive behavior in the primary motor cortex (M1) is debated. Here we recorded neural activity simultaneously from the brain surface as well as at different depths of the bilateral S1/M1 in freely-moving male rats receiving nociceptive stimulation. GBOs measured from superficial layers of S1 contralateral to the stimulated paw not only had the largest magnitude, but also showed the strongest temporal and phase coupling with epidural GBOs. Also, spiking of superficial S1 interneurons had the strongest phase coherence with epidural GBOs. These results provide the first direct demonstration that scalp GBOs, one of the most promising pain biomarkers, reflect neural activity strongly coupled with the fast spiking of interneurons in the superficial layers of the S1 contralateral to the stimulated side.