Encoding of the unpleasantness of pain in cortico-striatal neurons of the Anterior Cingulate Cortex

CONSTANZA ILARRAZ; MARIO ACUÑA; THOMAS NEVIAN; FERNANDO KASANETZ

París

Congreso; FENS Forum 2022; 2022

Federation of European Neuroscience Societies (FENS)

The perception of pain is a multidimensional sensory and emotional/affective experience arising from distributed brain activity. Maladaptive changes in the so called pain matrix are thought to play a role in the chronification of pain. However, how the brain encodes the perception of pain is still elusive. In particular, little is known about the neuronal activity patterns associated to the unpleasantness that characterizes the pain experience. One of the reasons for this caveat is that in preclinical models, pain was traditionally evaluated by means of reflexive responses. Recently, more attention has been devoted to the affective-motivational consequences of pain, which are complex behaviors that reflect the subject’s motivation to make the aversive sensation cease and that require processing of nociceptive information in cortico-limbic circuits. In order to investigate real-time cortical encoding of the unpleasantness of pain, we first characterized the behavioral repertoire in response to noxious stimuli in female and male mice. We observed that naïve females expressed higher selfattending responses to noxious cold than naïve males, whereas neuropathic pain increased affective/motivational behaviors in both sexes. Then, using in vivo calcium imaging with a miniature microscope, we monitored neuronal activity in cortico-striatal neurons of the Anterior Cingulate Cortex (CS-ACC), a cell population that may converge nociceptive information to the mesolimbic system. Our preliminary results show that while some neurons responded specifically to sensory stimuli, others encoded preferentially the behavioral manifestation of pain. Thus, our data suggest that CS-ACC neurons may encode a broad variety of information associated to noxious stimuli.