October 17, 2023 : A recent study published in Molecular Psychiatry found that chronic cocaine exposure upregulates hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in ventral tegmental area (VTA) dopamine neurons. This upregulation of HCN channels promotes cocaine reinforcement, or the motivation to seek and consume cocaine.
HCN channels are ion channels activated by hyperpolarization, meaning they open when the cell membrane becomes more negative. HCN channels play an important role in regulating neuronal excitability and firing patterns.
The study found that cocaine exposure increased the expression and activity of HCN channels in VTA dopamine neurons. This increase in HCN channel activity led to a decrease in the excitability of VTA dopamine neurons, making them less likely to fire.
The researchers also found that inhibiting HCN channels in VTA dopamine neurons reduced cocaine reinforcement. This suggests that HCN channels play a key role in mediating the reinforcing effects of cocaine.
The findings of this study have important implications for developing new treatments for cocaine addiction. By targeting HCN channels, researchers may be able to develop new drugs that can reduce cocaine reinforcement and help people overcome their addiction.