Publications by Ralf Schneggenburger

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

Ralf Schneggenburger, Olexiy Kochubey, Shriya Palchaudhuri, Denys Osypenko

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, Shriya Palchaudhuri, Denys Osypenko, Christos Sourmpis

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

Fear Learning: An Evolving Picture for Plasticity at Synaptic Afferents to the Amygdala

Ralf Schneggenburger, Shriya Palchaudhuri, Denys Osypenko

Unraveling the neuronal mechanisms of fear learning might allow neuroscientists to make links between a learned behavior and the underlying plasticity at specific synaptic connections. In fear learning, an innocuous sensory event such as a tone (called the ...

SAGE PUBLICATIONS INC2022

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

LTP of inhibition at PV interneuron output synapses requires developmental BMP signaling

Ralf Schneggenburger, Evan Dean Vickers, Christopher Clark, Denys Osypenko

Parvalbumin (PV)-expressing interneurons (PV-INs) mediate well-timed inhibition of cortical principal neurons, and plasticity of these interneurons is involved in map remodeling of primary sensory cortices during critical periods of development. To assess ...

Nature Research2020

Optogenetic Stimulation of Basal Forebrain Parvalbumin Neurons Activates the Default Mode Network and Associated Behaviors

Ralf Schneggenburger, Jayakrishnan Harikrishnavilas Raveendran Nair, Gregor Rainer, Laura Lozano Montes, Michael Kintscher

Activation of the basal forebrain (BF) has been associated with increased attention, arousal, and a heightened cortical representation of the external world. In addition, BF has been implicated in the regulation of the default mode network (DMN) and associ ...

2020

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

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

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

Role of BMP Signaling for the Formation of Auditory Brainstem Nuclei and Large Auditory Relay Synapses

Ralf Schneggenburger, Elin Kristina Kronander, Christopher Clark

Large excitatory synapses are found at specific points in the neuronal circuits of the auditory brainstem, to enable fast information transfer and the preservation of acoustic timing information. The extracellular cues and signaling mechanisms that lead to ...

WILEY2019

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

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

2018

Specific synaptic input strengths determine the computational properties of excitation-inhibition integration in a sound localization circuit

Ralf Schneggenburger, Friedemann Zenke, Enida Gjoni, Brice Antoine Alexandre Bouhours

The lateral superior olive (LSO) is a binaural nucleus in the auditory brainstem in which excitation from the ipsilateral ear is integrated with inhibition from the contralateral ear. It is unknown whether the strength of the unitary inhibitory and excitat ...

WILEY2018

Ultrastructural basis of strong unitary inhibition in a binaural neuron

Graham Knott, Ralf Schneggenburger, Enida Gjoni, Clémentine Léa Aguet

Binaural neurons in the lateral superior olive (LSO) integrate sound information arriving from each ear, and powerful glycinergic inhibition of these neurons plays an important role in this process. In the present study, we investigated the ultrastructural ...

WILEY2018

A cortico-thalamic-hippocampal circuit for remote fear memory attenuation

Ralf Schneggenburger, Johannes Gräff, Michael Kintscher, Bianca Ambrogina Silva

Springer Wien2017

An organotypic slice culture to study the formation of calyx of Held synapses in-vitro

Ralf Schneggenburger, Elin Kristina Kronander

The calyx of Held, a large axo-somatic relay synapse containing hundreds of presynaptic active zones, is possibly the largest nerve terminal in the mammalian CNS. Studying its initial growth in-vitro might provide insights into the specification of synapti ...

2017

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

RIM1 and RIM2 redundantly determine Ca2+ channel density and readily releasable pool size at a large hindbrain synapse

Ralf Schneggenburger, Yunyun Han, Zsolt Norbert Babai

The localization and density of voltage-gated Ca2+ channels at active zones are essential for the amount and kinetics of transmitter release at synapses. RIM proteins are scaffolding proteins at the active zone that bind to several other presynaptic protei ...

American Physiological Society2015

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

Henry Markram, Ralf Schneggenburger, Felix Schürmann, Yunyun Han, Olexiy Kochubey, 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

Molecular mechanisms governing Ca2+ regulation of evoked and spontaneous release

Ralf Schneggenburger

The relationship between transmitter release evoked by action potentials and spontaneous release has fascinated neuroscientists for half a century, and separate biological roles for spontaneous release are emerging. Nevertheless, separate functions for spo ...

2015