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Mojica Soto-Albors, R.

Publications and source records attributed to Mojica Soto-Albors, R..

2 recordsLinked to original sources

Plateau potentials are instructive signals for behavioral timescale synaptic plasticity in the neocortex

Learning occurs via the adjustment of synaptic weights across a variety of timescales. The mechanisms supporting these processes, from single-shot to iterative learning, are unclear. The prevailing model in the neocortex, spike-timing dependent plasticity (STDP), requires many pairings of precisely coordinated activity. This is difficult to reconcile with single-shot learning in behaving animals. In hippocampus, an alternative form of plasticity driven by plateau potentials (behavioral timescale synaptic plasticity; BTSP) alters synaptic weights in a single trial to reorganize spatial representations. Here we show that layer 5 pyramidal neurons (L5 PNs) of mouse primary visual cortex (V1) exhibit highly prevalent plateau potentials that drive single-shot changes in sensory representations. Spontaneously occurring and experimentally induced plateaus rapidly and persistently modified L5 PN responses to visual stimuli. In acute slices, plateau potentials drove synapse-specific plasticity with few repetitions across seconds-long pairing intervals. Our results demonstrate that plateau potentials in the neocortex rapidly reshape neuronal representations through BTSP. This instructive form of plasticity provides a mechanism for dynamic adjustment of neocortical synaptic weights to support rapid learning.

neuroscience↗

Representation of Visual Landmarks in Retrosplenial Cortex

The process by which visual information is incorporated into the brains spatial framework to represent landmarks is poorly understood. Studies in humans and rodents suggest that retrosplenial cortex (RSC) plays a key role in these computations. We developed an RSC-dependent behavioral task in which head-fixed mice learned the spatial relationship between visual landmark cues and hidden reward locations. Two-photon imaging revealed that these cues served as dominant reference points for most task-active neurons and anchored the spatial code in RSC. Presenting the same environment but decoupled from mouse behavior degraded encoding fidelity. Analyzing visual and motor responses showed that landmark codes were the result of supralinear integration. Surprisingly, V1 axons recorded in RSC showed similar receptive fields. However, they were less modulated by task engagement, indicating that landmark representations in RSC are the result of local computations. Our data provide cellular- and network-level insight into how RSC represents landmarks.

neuroscience↗