Firing patterns of ventral hippocampal neurons predict the exploration of anxiogenic locations

Abstract

The ventral hippocampus (vH) plays a crucial role in anxiety-related behaviour and vH neurons increase their firing when animals explore anxiogenic environments. However, if and how such neuronal activity induces or restricts the exploration of an anxiogenic location remains unexplained. Here, we developed a novel behavioural paradigm to motivate rats to explore an anxiogenic area. Male rats ran along an elevated linear maze with protective sidewalls, which were subsequently removed in parts of the track to introduce an anxiogenic location. We recorded neuronal action potentials during task performance and found that vH neurons exhibited remapping of activity, overrepresenting anxiogenic locations. Direction-dependent firing was homogenised by the anxiogenic experience. We further showed that the activity of vH neurons predicted the extent of exploration of the anxiogenic location. Our data suggest that anxiety-related firing does not solely depend on the exploration of anxiogenic environments, but also on intentions to explore them.

Exposure to Progestin 17-OHPC Induces Gastrointestinal Dysfunction through Claudin-1 Suppression in Female Mice with Increased Anxiety-Like Behaviors

“…However, there is no discernible effect on SYP expression in these areas [ 29 ]. While 17-OHPC exposure induces anxiety-like behaviors in mice, it does not trigger autism-like behaviors, suggesting that progestin exposure may modulate women’s mood, including anxiety, fear, and depression [ 4 , 30 , 31 ].…”

Differential encoding of fear learning and fear expression in the ventral and dorsal hippocampus

“…First, the precision of spatial coding diminishes along the dorsoventral axis of the HPC 8–10 . Second, neurons in more ventral parts of the HPC exhibit a stronger association with the emotional valence of locations 11–14 and odors 15 as compared to the dHPC. Furthermore, optogenetic studies further suggest that specific pathways between the basolateral amygdala (BLA) and vHPC are recruited during anxiety and fear-related behaviors 12,16–18 .…”

“…This result failed to support our initial hypothesis, and was surprising given the ample published evidence for a role of vHPC in controlling anxiety and fear behavior. 12,14,16,17,22 A possible explanation for the dHPC freezing-associated inhibition would be related to the motor, rather than the emotional, aspects of freezing. Previous work had shown that activity in dHPC is modulated more by animals' speed than vHPC.…”