Kudo, T., Tahara, Y., Gamble, K.L., McMahon, D.G., Block, G.D., and Colwell, C.S. (2013). Vasoactive intestinal peptide produces long-lasting changes in neural activity in the suprachiasmatic nucleus. J Neurophys, Sep;110(5):1097-106.

The neuropeptide vasoactive intestinal peptide (VIP) is expressed at high levels in the neurons of the suprachiasmatic nucleus (SCN). While VIP is known to be important to the input and output pathways from the SCN, the physiological effects of VIP on electrical activity of SCN neurons are not well known. Here the impact of VIP on firing rate of SCN neurons was investigated in mouse slice cultures recorded during the night. The application of VIP produced an increase in electrical activity in SCN slices that lasted several hours after treatment. This is a novel mechanism by which this peptide can produce long-term changes in central nervous system physiology.

Peptidergic expression and release is critical for neural control in the brain. The peptide under investigation here, VIP, has been shown to have long-term effects on a neurons electrical activity which then effects the neural output from the primary clock in the brain, primarily through activation of fast delayed rectifier potassium currents.

Light therapy has been shown to enhance mood and treat sleep and affective disorders. The primary means by which light affects sleep and mood is through its effects on the brain’s clock in the suprachiasmatic nucleus (SCN). SCN neurons release a very important peptide, VIP, and the current study links long-term effects of VIP to changes in neural firing rate and potassium current modification.