Network dynamics of nociceptive processing in the anterior cingulate cortex

FERNANDO KASANETZ; MIRKO SANTELLO; THOMAS NEVIAN

San Diego

Congreso; SFN annual meeting 2016; 2016

Society for Neuroscience

The Anterior Cingulate Cortex (ACC) plays a central role in the interpretation and evaluation of the affective and emotional components of pain. Accumulating evidence indicates that abnormal neuronal plasticity and a resulting hyperactivity of the ACC is the cause for the manifestation of the emotional distress that characterizes chronic pain conditions. However, little is known on how the functional organization of ACC microcircuits is affected in chronic pain. Apart from its involvement in pain perception, the ACC is engaged in a variety of other cognitive and emotional processes such as working memory, inhibitory control, conflict monitoring, fear, attention, salience and reward expectancy. How neuronal populations in the ACC can be involved in such a diversity of functions is a matter of debate. One intriguing hypothesis would be that the ACC is composed of multiple sub-circuits mediating separate aspects of behavior. Here we addressed whether the ACC possesses specialized neurons that process nociceptive information and how this putative microcircuit organization is affected in chronic neuropathic pain. We also focused on the role and activity of dendritic sub-compartments of pyramidal neurons in information processing in the ACC. Using in vivo recording of spiking activity in the mouse ACC, we have identified a subpopulation of neurons that are activated in response to nociceptive stimulation. Interestingly, this ?nociceptive neurons? showed a preferential increase in spontaneous activity during chronic pain, suggesting that ACC hyperactivity might be restricted to a sub-network of pain-related cells. In order to gain insight into the organization and plasticity of the ACC, we will present data combining in vivo two-photon calcium imaging of neuronal populations and dendritic sub-compartments with neuronal tracing and synaptic silencing techniques to uncover the functional properties and neuronal identity of ACC ?nociceptive neurons? and its modulation by chronic pain.