Journal Club 25-1-14

Processing of pain and itch information by modality-specific neurons within the anterior cingulate cortex in mice

Hyoung-Gon Ko 1,2 ,HyunsuJung 3,4,9, Seunghyo Han1,9, Dong Il Choi4,9,
Chiwoo Lee4,9, Ja Eun Choi4,JihaeOh4,ChuljungKwak3,DaeHeeHan3,
Jun-Nyeong Kim1,SanghyunYe 4,JiahLee4,JaehyunLee4,KyungminLee 5,
Jae-Hyung Lee 6,MinZhuo7,8 & Bong-Kiun Kaang3,

Pain and itch are aversive sensations with distinct qualities, processed in
overlapping pathways and brain regions, including the anterior cingulate
cortex (ACC), which is critical for their affective dimensions. However, the
cellular mechanisms underlying their processing in the ACC remain unclear.
Here, we identify modality-specific neuronal populations in layer II/III of the
ACC in mice involved in pain and itch processing. Using a synapse labeling
tool, we show that pain- and itch-related neurons selectively receive synaptic
inputs from mediodorsal thalamic neurons activated by pain and itch stimuli,
respectively. Chemogenetic inhibition of these neurons reduced pruriception
ornociception without affecting the opposite modality. Conversely, activation
of these neurons did not enhance stimulus-specific responses but commonly
increased freezing-like behavior. These findings reveal that the processing of
itch and pain information in the ACC involves activity-dependent and
modality-specific neuronal populations, and that functionally distinct ACC neuronal subsets process pain and itch