Craving is a major driver of relapse in drug addiction. In people who use methamphetamine—one of the most widely used synthetic drugs in China—craving can grow stronger during abstinence, a phenomenon known as the incubation of craving. With current treatments offering limited protection against relapse, researchers are seeking to understand the brain mechanisms behind this increase.
The prelimbic cortex (PL), a region of the prefrontal cortex involved in executive control, plays an important role in drug-seeking behaviour. A study led by Professors Min Zhao, Ti-Fei Yuan, and Fang Liu at Shanghai Jiao Tong University’s School of Psychology and Shanghai Mental Health Center was published in Neuron on 25 March 2026. The paper is entitled “Circuit and molecular mechanisms underlying incubation of methamphetamine craving in the prelimbic cortex”. Using mouse models, the researchers found that somatostatin-expressing (SST) and parvalbumin-expressing (PV) interneurons regulate methamphetamine seeking during early and prolonged withdrawal, respectively, through distinct neural circuits. They also identified KCNC2, which encodes the Kv3.2 potassium channel, as a regulator of interneuron firing and a potential target for stage-specific interventions.
1. Inhibitory control shifts over time
Most studies of the PL in addiction have focused on excitatory glutamatergic neurons. Much less is known about its inhibitory interneurons, including whether different subtypes shape craving at different stages of withdrawal.
To investigate this, the team used a mouse model in which animals self-administered methamphetamine before entering withdrawal. The researchers tracked SST and PV interneurons using c-Fos staining, activity-dependent neuronal labelling, and fibre photometry. On the first day of withdrawal, SST interneurons were less active. Further experiments showed that impaired SST function promoted early drug seeking. By day 15, PV interneurons were strongly activated and drove the time-dependent increase in drug seeking. These results reveal that the two inhibitory interneuron populations play distinct roles as withdrawal progresses.
2. A circuit switch during withdrawal
Circuit tracing and functional experiments revealed that different pathways drive methamphetamine seeking at different stages of withdrawal. Early on, GABAergic projections from the lateral hypothalamus (LH) suppressed SST interneurons in the PL. This disrupted the local balance between excitation and inhibition and promoted drug seeking through the LHGABA-PLSST pathway. After prolonged withdrawal, glutamatergic projections from the anteromedial thalamus (AM) activated PV interneurons in the PL and drove incubated drug seeking through the AMGlu-PLPV pathway. Together, these findings reveal a stage-dependent shift in the neural circuits underlying methamphetamine craving.
3. How KCNC2 and Kv3.2 shape interneuron activity during withdrawal
Single-cell RNA sequencing identified KCNC2, which encodes Kv3.2, a potassium channel that supports rapid neuronal firing. KCNC2 expression rose in SST interneurons during early withdrawal and in PV interneurons after prolonged withdrawal, but the effects were different. Early in withdrawal, increased phosphorylation Kv3.2 weakened channel activity and limited rapid firing in SST interneurons. After prolonged withdrawal, higher Kv3.2 protein levels allowed PV interneurons to fire more rapidly.
To test whether KCNC2 contributes to drug seeking, the researchers reduced its expression in each cell type. Knocking down KCNC2 in SST interneurons reduced seeking during early withdrawal, whereas knockdown in PV interneurons had the same effect after prolonged withdrawal. The results identify KCNC2/Kv3.2 as a molecular link between withdrawal stage, interneuron activity, and drug seeking—and as a possible target for treatments matched to different stages of withdrawal.
4. Implications for stage-specific treatment
The findings show that craving is not driven by a single, fixed mechanism. Instead, the neurons and circuits involved change as withdrawal progresses. This raises the possibility that treatments could be matched to the stage of withdrawal.
Future studies could test whether drugs or neuromodulation techniques, such as transcranial magnetic stimulation (TMS) and focused ultrasound stimulation (FUS), can influence the circuits involved at each stage. KCNC2/Kv3.2 may offer another target for drug development because it acts in both SST and PV interneurons at different time points. The work was conducted in mice, and whether the same mechanisms operate in people with methamphetamine use disorder remains to be tested.
Paper doi: https://doi.org/10.1016/j.neuron.2026.02.017
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