Publications de Olexiy Kochubey

A posterior insula to lateral amygdala pathway transmits US-offset information with a limited role in fear learning

Ralf Schneggenburger, Olexiy Kochubey, Denys Osypenko, Shriya Palchaudhuri

During fear learning, associations between a sensory cue (conditioned stimulus, CS) and an aversive stimulus (unconditioned stimulus, US) are formed in specific brain circuits. The lateral amygdala (LA) is involved in CS-US integration; however, US pathway ...

2025

Auditory stimuli suppress contextual fear responses in safety learning independent of a possible safety meaning

Ralf Schneggenburger, Olexiy Kochubey, Johanni Michael Brea, Christos Sourmpis, Denys Osypenko, Shriya Palchaudhuri

Safety learning allows the identification of non-threatening situations, a learning process instrumental for survival and psychic health. In contrast to fear learning, in which a sensory cue (conditioned stimulus, CS) is temporally linked to a mildly avers ...

2024

A striatal circuit balances learned fear in the presence and absence of sensory cues

Ralf Schneggenburger, Olexiy Kochubey, Michael Kintscher

During fear learning, defensive behaviors like freezing need to be finely balanced in the presence or absence of threat-predicting cues (conditioned stimulus, CS). Nevertheless, the circuits underlying such balancing are largely unknown. Here, we investiga ...

eLIFE SCIENCES PUBL LTD2023

Stimulation of medial amygdala GABA neurons with kinetically different channelrhodopsins yields opposite behavioral outcomes

Ralf Schneggenburger, Olexiy Kochubey, Aiste Baleisyte

The medial amygdala (MeA) receives pheromone information about conspecifics and has crucial functions in social behaviors. A previous study showed that activation of GABA neurons in the postero-dorsal MeA (MeApd) with channelrhodopsin-2(H)(134R) (ChR2) sti ...

CELL PRESS2022

A VTA to Basal Amygdala Dopamine Projection Contributes to Signal Salient Somatosensory Events during Fear Learning

Ralf Schneggenburger, Olexiy Kochubey, Wei Tang, Michael Kintscher

The amygdala is a brain area critical for the formation of fear memories. However, the nature of the teaching signal(s) that drive plasticity in the amygdala are still under debate. Here, we use optogenetic methods to investigate the contribution of ventra ...

2020

RETRACTED: Insular cortex processes aversive somatosensory information and is crucial for threat learning

Ralf Schneggenburger, Olexiy Kochubey, Wei Tang, Michael Kintscher, Denys Osypenko, Shriya Palchaudhuri, Emmanuelle Marie Brigitte Berret

Learning about threats is essential for survival. During threat learning, an innocuous sensory percept such as a tone acquires an emotional meaning when paired with an aversive stimulus such as a mild footshock. The amygdala is critical for threat memory f ...

American Association for the Advancement of Science2019

Parvalbumin-Interneuron Output Synapses Show Spike-Timing-Dependent Plasticity that Contributes to Auditory Map Remodeling

Ralf Schneggenburger, Olexiy Kochubey, Christopher Clark, Denys Osypenko, Alex Fratzl, Evan Dean Vickers

2018

Synaptotagmin2 (Syt2) Drives Fast Release Redundantly with Syt1 at the Output Synapses of Parvalbumin-Expressing Inhibitory Neurons

Ralf Schneggenburger, Olexiy Kochubey, Enida Gjoni, Brice Antoine Alexandre Bouhours

Parvalbumin-expressing inhibitory neurons in the mammalian CNS are specialized for fast transmitter release at their output synapses. However, the Ca2+ sensor(s) used by identified inhibitory synapses, including the output synapses of parvalbumin-expressin ...

2017

A Synaptotagmin Isoform Switch during the Development of an Identified CNS Synapse

Ralf Schneggenburger, Olexiy Kochubey, Zsolt Norbert Babai

Various Synaptotagmin (Syt) isoform genes are found in mammals, but it is unknown whether Syts can function redundantly in a given nerve terminal, or whether isoforms can be switched during the development of a nerve terminal. Here, we investigated the pos ...

2016

An Exclusion Zone for Ca2+ Channels around Docked Vesicles Explains Release Control by Multiple Channels at a CNS Synapse

Henry Markram, Ralf Schneggenburger, Olexiy Kochubey, Felix Schürmann, Yunyun Han, Daniel Keller, Zsolt Norbert Babai

The spatial arrangement of Ca2+ channels and vesicles remains unknown for most CNS synapses, despite of the crucial importance of this geometrical parameter for the Ca2+ control of transmitter release. At a large model synapse, the calyx of Held, transmitt ...

Public Library Science2015