Biology subjects

Sivroni, S.

Publications and source records attributed to Sivroni, S..

3 recordsLinked to original sources

bioRxiv2023

Wired together, change together: Spike timing modifies transmission in converging assemblies

Precise timing of neuronal spikes may lead to changes in synaptic connectivity and is thought to be crucial for learning and memory. However, the effect of spike timing on neuronal connectivity in the intact brain remains unknown. Using closed-loop optogenetic stimulation in CA1 of freely-moving mice, we generated new spike patterns between presynaptic pyramidal cells (PYRs) and postsynaptic parvalbumin-immunoreactive (PV) cells. This stimulation led to spike transmission changes which occurred together across all presynaptic PYRs connected to the same postsynaptic PV cell. The precise timing of all presynaptic and postsynaptic cells spikes impacted transmission changes. These findings reveal an unexpected plasticity mechanism, wherein spike timing of a whole cell assembly has a more substantial impact on effective connectivity than that of individual cell pairs.

neuroscience↗

bioRxiv2023

Short-term auditory priming in freely-moving mice

Priming, a change in the mental processing of a stimulus as a result of prior encounter with a related stimulus, has been observed repeatedly and studied extensively. Yet currently there is no behavioral model of short-term priming in lab animals, limiting the study of the neurobiological basis of priming. Here, we describe an auditory discrimination paradigm for studying response priming in freely-moving mice. We find a priming effect in success rate in all mice tested on the task. In contrast to humans, we do not find a priming effect in response times. Compared to non-primed discrimination trials, the addition of incongruent prime stimuli reduces success rate more than congruent prime stimuli, suggesting a cognitive mechanism based on differential interference. The results establish the short-term priming phenomenon in rodents, and the paradigm opens the door to studying the cellular-network basis of priming.

neuroscience↗

bioRxiv2022

Hybrid offspring of C57BL/6J mice exhibit improved properties for neurobehavioral research

C57BL/6 is the most commonly used mouse strain in neurobehavioral research, serving as a background for multiple transgenic lines. However, C57BL/6 exhibit behavioral and sensorimotor disadvantages that worsen with age. We bred FVB/NJ females and C57BL/6J males to generate first-generation hybrid offspring, (FVB/NJ x C57BL/6J)F1. The hybrid mice exhibit reduced anxiety-like behavior, improved learning, and enhanced long-term spatial memory. In contrast to both progenitors, older hybrids maintain sensorimotor performance and exhibit improved long-term memory. The hybrids are larger than C57BL/6J, exhibiting enhanced running behavior on a linear track during freely-moving electrophysiological recordings. Hybrids exhibit typical rate and phase coding of space by CA1 pyramidal cells. Hybrids generated by crossing FVB/NJ females with transgenic males of a C57BL/6 background support optogenetic neuronal control in neocortex and hippocampus. The hybrid mice provide an improved model for neurobehavioral studies combining complex behavior, electrophysiology, and genetic tools readily available in C57BL/6 mice.

neuroscience↗