Prepronociceptin-Expressing Neurons in the Bed Nucleus of the Stria Terminalis Signal Escape Behavior.

BACKGROUND

Dysregulation in neural circuits that encode arousal responses to aversive stimuli is thought to contribute to changes in motivated behaviors associated with neuropsychiatric disorders. However, the relationship between arousal and motivation remains poorly understood. We previously identified that prepronociceptin-expressing neurons in the bed nucleus of the stria terminalis ( neurons) modulate rapid physiological arousal responses to a motivationally salient aversive odor. However, whether neurons also signal behavioral actions triggered by an aversive odor is still unknown.

METHODS

In this study, we investigated the role of neurons in signaling behavioral responses to an aversive odor. We leveraged miniaturized head-mounted microscopes to monitor the calcium activity of neurons in vivo while freely behaving mice performed an odor preference test.

RESULTS

We found that the bulk activity of neurons increased as mice approached an aversive odor. Single-cell analyses revealed heterogeneity in response dynamics within the neuronal population upon initial exposure to the odor. Subsequent analysis revealed that the response dynamics of neurons that showed excitation when mice were in close proximity to the aversive odor were due to the initiation of darting away from the odor.

CONCLUSIONS

These results highlight a novel role of neurons to signal escape behavior in response to an aversive stimulus. This, in combination with our previous findings that neurons encode arousal responses, supports a neurobiological relationship of arousal and motivation within extended amygdala circuits.