Biology subjects

Vetere, G.

Publications and source records attributed to Vetere, G..

3 recordsLinked to original sources

bioRxiv2024

Plasticity of visual looming response reveals a dissociation of innate and learned components

Animals rely on innate and learned behaviour to respond to their environment, but how the brain balances hardwired responses with adaptive flexibility remains unclear. Here, we demonstrate that innate looming stimulus responses in mice can be attenuated via repeated unreinforced presentation. This attenuation is long-lasting and generalising, but is rapidly recovered when the stimulus is paired with an electric foot-shock. Fiber photometry recordings reveal attenuation of responses to visual looming stimuli in the SC and PAG, which do not recover following recovery of behavioural responses. Analysis of c-Fos expression uncovered a ventral CA1 (vCA1) ensemble that is active during both innate and learned looming fear responses. We report that this vCA1 engram is not necessary for innate defensive behaviour but is necessary for learned fear responses. These findings reveal a novel role of the hippocampus in adapting to looming stimuli, and provide a platform for understanding the interaction of memory and instinct.

neuroscience↗

bioRxiv2024

Deconstruction of a memory engram reveals distinct ensembles recruited at learning

How are associative memories formed? Which cells represent a memory, and when are they engaged? By visualizing and tagging cells based on their calcium influx with unparalleled temporal precision, we identified non-overlapping dorsal CA1 neuronal ensembles that are differentially active during associative fear memory acquisition. We dissected the acquisition experience into periods during which salient stimuli were presented or certain mouse behaviors occurred and found that cells associated with specific acquisition periods are sufficient alone to drive memory expression and contribute to fear engram formation. This study delineated the different identities of the cell ensembles active during learning, and revealed, for the first time, which ones form the core engram and are essential for memory formation and recall.

neuroscience↗

bioRxiv2023

Threat-dependent scaling of prelimbic dynamics to enhance fear representation

Promptly identifying threatening stimuli is crucial for survival. Freezing is a natural behavior displayed by rodents towards potential or actual threats. While it is known that the prelimbic cortex (PL) is involved in both risk evaluation and in fear and anxiety-like behavior expression, here we explored whether PL neuronal activity can dynamically represent different internal states of the same behavioral output. We found that freezing can always be decoded from PL activity at a population level. However, the sudden presentation of a fearful stimulus quickly reshaped PL to a new neuronal activity state, an effect not observed in other cortical or subcortical regions. This shift changed PL freezing representation and is necessary for fear memory expression. Our data reveal the unique role of PL in detecting threats and internally adjusting to distinguish between different freezing-related states. IN BRIEFThrough a comparative analysis across brain regions and risk situations, we demonstrate the distinctive role of the Prelimbic Cortex (PL) in fear-related behavior representation: the PL promptly detects threat stimuli and adjusts its neuronal configuration accordingly, resulting in a change in freezing representation, which is necessary for memory-associated fear expression. HIGHLIGHTS- PL population activity represents fear-related behavior (i.e., freezing) - Same behavioral outcome (freezing) can be represented as different PL neuronal states - Other brain regions do not show changes in dynamics to represent freezing - PL dynamics following threats are necessary for proper fear memory expression

neuroscience↗