Research

In the past years, we at the Korpi lab have focused on the long-term effects of the GABAA receptor modulating drugs, and on their effects on the dopamine neurons of the ventral tegmental area (VTA), and on other drugs that might counteract the effects of the drugs of abuse.

Closely tying into these themes, the effects and mechanisms of action of ethanol have been another overarching theme in the research of the lab, as also demonstrated by a recent review on .

As a part of the decades-long research programme, we have for example found that single ex vivo exposures to addictive, dependence-causing, synaptically active benzodiazepines, diazepam and zolpidem, and to two non-benzodiazepines, extrasynaptically active gaboxadol and ganaxolone, induce glutamate receptor neuroadaptation in mouse . This process involves cellular plasticity and represents long-lasting neuroadaptation of the glutamatergic system in the VTA through, at the systems level, the .

Interestingly, these latter drugs do not show rewarding properties in mice or baboons, but induce conditioned place aversion in mice. This result fits with a dichotomous functional/structural organization of VTA dopamine neuron populations both in monkeys and mice.

We have also found interesting "anti-addictive" effects of (a presynaptic Ca2+ channel downregulator) and (a GABAB receptor positive allosteric modulator) on the VTA neuroplasticity and behaviours induced by drugs of abuse.

The current projects of the lab, aiming to elaborate the neuronal circuits behind the addictive behaviours, are described below.

We have recently reviewed the of midbrain neurons as the critical part of for a number of drugs of abuse, and found that the idea of diverse populations of VTA dopamine and GABA neurons is still waiting for more detailed neurobiological and behavioural assessment and verification.

Present aims:

1. To establish the cellular heterogeneity and circuitry in the mouse midbrain, with the focus on the ventral tegmental area.
2. To link the VTA cellular subtypes to rewarding, emotional and/or cognitive behaviours.

Selected publications:

Nagaeva, Schäfer et al. Somatostatin-Expressing Neurons in the Ventral Tegmental Area Innervate Specific Forebrain Regions and Are Involved in Stress Response. 

Nagaeva et al. Heterogeneous somatostatin-expressing neuron population in mouse ventral tegmental area.

Nagaeva et al. Electrophysiological Properties of Neurons: Current-Clamp Recordings in Mouse Brain Slices and Firing-Pattern Analysis.

Main researchers: Elina Nagaeva, Annika Schäfer, Esa Korpi

Funded by: ,  

Serotonin is to play a part in the formation of addictive behavior. This has been interestingly reflected in clinical studies, conducted in between  and again more , showing that nonselective serotonin receptor agonists, psychedelics lysergic acid diethylamide (LSD) and psilocybin, can reduce alcohol drinking, and help people with .

In this new project we aim to elucidate the biological mechanisms behind these clinically shown effects.

Present aims:

1. To establish the back-translateability of the earlier clinical findings.
2. To elucidate the biological mechanism by which the mixed serotonin receptor agonists modulate the circuitries involved in addicition. 

Selected publications:

Elsilä et al. Effects of acute lysergic acid diethylamide on intermittent ethanol and sucrose drinking and intracranial self-stimulation in C57BL/6 mice.

Elsilä et al. Acute Lysergic Acid Diethylamide Does Not Influence Reward-Driven Decision Making of C57BL/6 Mice in the Iowa Gambling Task. 

Hynninen et al. Psykedeelien kliiniset vaikutukset ja biologiset mekanismit. (review in Finnish)

Main researchers: Lauri Elsilä, Esa Korpi

Funded by: , , ,