Both kappa and mu opioid agonists inhibit glutamatergic input to ventral tegmental area neurons.

Opioid Agonists Inhibit Glutamatergic Input to Ventral Tegmental Area Neurons”

Opioid modulation of ventral pallidal afferents to ventral tegmental area neurons.

Activation of mu opioid receptors within the ventral tegmental area (VTA) can produce reward through the inhibition of GABAergic inputs. GABAergic neurons in the ventral pallidum (VP) provide a major input to VTA neurons. To determine the specific VTA neuronal targets of VP afferents and their sensitivity to mu opioid receptor agonists, we virally expressed channel rhodopsin (ChR2) in rat VP ne...

Kappa opioid inhibition of somatodendritic dopamine inhibitory postsynaptic currents.

In the midbrain, dopamine neurons can release dopamine somatodendritically. This results in an inhibitory postsynaptic current (IPSC) within adjacent dopamine cells that occurs by the activation of inhibitory D(2) autoreceptors. Kappa, but not mu/delta, opioid receptors inhibit this IPSC. The aim of the present study was to determine the mechanism by which kappa-opioid receptors inhibit the dop...

Presynaptic mu-opioid receptors regulate a late step of the secretory process in rat ventral tegmental area GABAergic neurons.

Gamma-aminobutyric acid (GABA)-containing interneurons of the ventral tegmental area (VTA) regulate the activity of dopaminergic neurons. These GABAergic interneurons are known to be innervated by synaptic terminals containing enkephalin, an endogenous ligand of mu-opioid receptors. Bath application of mu-opioid receptor agonists inhibits the activity of VTA GABAergic neurons but the mechanism ...

Yin and yang of VTA opioid signaling. Focus on "both kappa and mu opioid agonists inhibit glutamatergic input to ventral tegmental area neurons".

In opioid signaling in the brain and -opioid receptors (MOR and KOR) are like the yin and yang principles in Chinese philosophy, they always act as an opposing pair. The antagonistic interactions between MOR and KOR are widespread in the CNS. In few receptor families, two closely related members with such overlapping expression in the brain produce such opposite behavioral effects. In humans, M...