I am a
Home I AM A Search Login

Papers of the Week

Papers: 9 Feb 2019 - 15 Feb 2019

Animal Studies

2019 Jun




Distal infraorbital nerve injury (DIONI): a model for persistent facial pain in mice.


Hardt S, Fischer C, Vogel A, Wilken-Schmitz A, Tegeder I
Pain. 2019 Jun; 160(6):1431-1447.
PMID: 30747909.


Inflammation or injuries of the trigeminal nerve are often associated with persistent facial pain and its sequelae. A number of models have been described to study trigeminal pain in rodents, but the long-lasting behavioral consequences are unknown. The present study characterizes the impact of a distal infraorbital nerve injury, called DIONI, which consists of ligature and transection of distal fibers of the infraorbital nerve. We assessed nociception using a conflict paradigm and optogenetics, and a set of reward, aversion, spatial, temporal and competition tasks in the IntelliCage to study multiple aspects of cognition, circadian rhythms and social interactions in groups of mice in home cage environments. Mice with DIONI developed cold and mechanical allodynia, and hypersensitivity towards blue light stimulation. They maintained a long lasting memory of aversive stimuli (airpuff from above), but had no difficulty in learning appetitive tasks, which consisted of preference for a rewarding corner in the IntelliCage. Indeed, they were more strongly 'addicted' to sugar than sham mice but temporarily failed to re-learn the location of rewarding sites after corner switching (Reversal learning). They were mildly overactive in some tasks but without disruptions of circadian rhythms, or impact on social structure. They adopted a strategy to maintain licking with fewer nosepokes, presumably trying to avoid mechanical stimulation of the snout. The results suggest that mice with distal infraorbital nerve injury develop strong aversive memories and some cognitive inflexibility, but create adaptive strategies to cope with the persistent trigeminal hypersensitivity.