3 years ago

Dopamine and opioids inhibit synaptic outputs of the main island of the intercalated neurons of the amygdala

Gabrielle C Gregoriou, Sahil D Patel, Sarah A Kissiwaa, Elena E Bagley


Neural circuits in the amygdala are important for associating the positive experience of drug taking with the coincident environmental cues. During abstinence, cue re‐exposure activates the amygdala, increases dopamine release in the amygdala and stimulates relapse to drug use in an opioid dependent manner. Neural circuits in the amygdala and the learning that underlies these behaviours are inhibited by GABAergic synaptic inhibition. A specialised subtype of GABAergic neurons in the amygdala are the clusters of intercalated cells. We focussed on the main‐island of intercalated cells because these neurons, located ventromedial to the basolateral amygdala, express very high levels of dopamine D1‐receptor and mu‐opioid receptor, release enkephalin and are densely innervated by the ventral tegmental area. However, where these neurons project to was not fully described and their regulation by opioids and dopamine was incomplete. To address this issue we electrically stimulated in the main‐island of the intercalated cells in rat brain slices and made patch‐clamped recordings of GABAergic synaptics from amygdala neurons. We found that main‐island neurons had a strong GABAergic inhibitory output to pyramidal neurons of the basolateral nucleus and the medial central nucleus, the major output zones of the amygdala. Opioids inhibited both these synaptic outputs of the intercalated neurons and thus would disinhibit these target zones. Additionally, dopamine acting at D1‐receptors inhibited main‐island neuron synapses onto other main‐island neurons. This data indicates that the inhibitory projections from the main‐island neurons could influence multiple aspects of addiction and emotional processing in an opioid and dopamine dependent manner.

This article is protected by copyright. All rights reserved.

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.