Meletis Laboratory

The Meletis laboratory is investigating the circuit mechanisms that shape motivated behaviors and the circuit imbalance that underlies core phenotypes of mood disorders.

Meletis laboratory research focus

Research focus

A key to this investigation is the development and use of advanced technologies to probe the organization and function of candidate circuits, focusing on the basal ganglia, hypothalamus, habenula, and the serotonin system. The investigation of neurons and circuit is based on genetic access to neuron types in combination with technologies to record or manipulate neuronal activity with high temporal and spatial precision during behavioral tasks. 

The Meletis laboratory has developed and applied a number of methods to map circuit organization and function, ranging from advanced molecular methods to determine gene expression patterns in cells and tissue – to in vivo approaches to define the role of neurons in aversion and motivation. Functional circuit mapping as well as molecular definitions of cell types and brain regions are central to establish a comprehensive understanding of how neurons and circuits generate motivated behaviors.

  1. Optogenetic control of a Parvalbumin-expressing GABAergic interneuron.
  2. Circuit and behavior control through electronic interface board with LED and gyroscope.
  3. Corticostriatal circuit dissection with genetically modified viruses.

Group members

Selected publications

Complete representation of action space and value in all striatal pathways.
Weglage M, Warnberg E, Lazaridis I, Tzortzi O, Meletis K
Biorxiv, 28 August 2020, doi:

Molecular atlas of the adult mouse brain.
Ortiz C, Navarro JF, Jurek A, Märtin A, Lundeberg J, Meletis K
Sci Adv 2020 Jun;6(26):eabb3446

A Spatiomolecular Map of the Striatum.
Märtin A, Calvigioni D, Tzortzi O, Fuzik J, Wärnberg E, Meletis K
Cell Rep 2019 12;29(13):4320-4333.e5

A hypothalamus-habenula circuit controls aversion.
Lazaridis I, Tzortzi O, Weglage M, Märtin A, Xuan Y, Parent M, Johansson Y, Fuzik J, Fürth D, Fenno LE, Ramakrishnan C, Silberberg G, Deisseroth K, Carlén M, Meletis K
Mol Psychiatry 2019 09;24(9):1351-1368

A whole-brain atlas of monosynaptic input targeting four different cell types in the medial prefrontal cortex of the mouse.
Ährlund-Richter S, Xuan Y, van Lunteren JA, Kim H, Ortiz C, Pollak Dorocic I, Meletis K, Carlén M
Nat Neurosci 2019 04;22(4):657-668

An interactive framework for whole-brain maps at cellular resolution.
Fürth D, Vaissière T, Tzortzi O, Xuan Y, Märtin A, Lazaridis I, Spigolon G, Fisone G, Tomer R, Deisseroth K, Carlén M, Miller CA, Rumbaugh G, Meletis K
Nat Neurosci 2018 01;21(1):139-149

A whole-brain atlas of inputs to serotonergic neurons of the dorsal and median raphe nuclei.
Pollak Dorocic I, Fürth D, Xuan Y, Johansson Y, Pozzi L, Silberberg G, Carlén M, Meletis K
Neuron 2014 Aug;83(3):663-78

Contact us

Contact information for the Meletis Lab at the Department of Neuroscience, Karolinska Institutet.

Postal address

Karolinska Institutet
Department of Neuroscience
171 77 Stockholm

Visiting address (visitors, couriers, etc.)

Karolinska Institutet
Biomedicum, Quarter B4
Solnavägen 9
171 65 Solna

Delivery address (goods, parcels, etc.)

Tomtebodavägen 16
171 65 Solna

Karolinska Institutet, Biomedicum, Solnavägen 9

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