Biology subjects

Cataldi, S.

Publications and source records attributed to Cataldi, S..

3 recordsLinked to original sources

bioRxiv2025

Safety learning induces postsynaptic potentiation of direct pathway spiny projection neurons in the tail of the striatum

The association of a sensory cue with an outcome is a crucial step in learning to identify safe versus threatening situations. Here we assessed how learned sound-safety association alters neuronal activity in tail of the striatum (TS), where auditory cortical and thalamic inputs converge. Prior to training, foot shock elicited responses by TS direct and indirect pathway spiny projection neurons (SPNs), while sound tones produced no response. However, once the sound association was learned, sound tones strongly activated TS SPNs, even when the animal was under anesthesia. This conditioned auditory response occurred concurrently with alterations of direct pathway SPNs in the TS, including increased responses to cortical and auditory thalamic inputs, increased excitatory response with an enhanced ratio of NMDA to AMPA receptors, decreased responses to inhibitory input, and increased dendritic spines. This convergence of postsynaptic changes provides responses to relevant auditory cues during associative learning. TeaserSound-safety association enhances response to learned sound in striatal neurons via postsynaptic mechanisms

neuroscience↗

bioRxiv2021

Activity in the dorsomedial striatum decreases with improvement in motor coordination

It has been suggested that the dorsomedial striatum (DMS) facilitates the early stages of motor learning for goal-directed actions, whereas at later stages, control is transferred to the dorsolateral striatum (DLS), which enables the motor actions to become a skill or habit. It is unknown whether these striatal regions are simultaneously active while expertise is acquired during skill learning. To address this question, we developed the "treadmill training task" to track changes in mouse locomotor coordination during practice at running that simultaneously provides a means to measure local neuronal activity using photometry. We analyzed body position and paw movement to evaluate changes in motor coordination over practice sessions on the treadmill using DeepLabCut and custom-built code. By correlating improvements in motor coordination during training with simultaneous neuronal calcium activity in the striatum, we found that DMS direct pathway neurons exhibited decreased activity as the mouse gains proficiency at running. In contrast, direct pathway activity in the DLS was similar throughout training and did not correlate with learned skill proficiency. Pharmacological blockade of D1 dopamine receptors in these subregions during task performance confirmed that dopamine neurotransmission in the DMS direct pathway activity is necessary for efficient motor coordination learning, while dopamine signalling in the DLS is important for both coordination learning and maintenance of the acquired skill. These results provide new tools to measure changes in fine motor skills during simultaneous recordings of brain activity, revealing fundamental features of the neuronal substrates of motor learning.

neuroscience↗

bioRxiv2020

α-Synuclein facilitates dopamine release during burst firing of substantia nigra neurons in vivo

-Synuclein is expressed at high levels at presynaptic terminals, but defining its role on neurotransmission under physiologically-relevant conditions has proven elusive. We report that -synuclein is responsible for a rapid facilitation of dopamine release during action potential bursts in vivo. This occurs in tandem with a far slower stimulus-dependent depression, appears to be independent of the presence of {beta}- and {gamma}-synucleins or effects on presynaptic calcium and is consistent with a role for synucleins in the enhancement of synaptic vesicle fusion and turnover. The results indicate that the presynaptic effects of -synuclein are dependent on specific patterns of neuronal activity.

neuroscience↗