single-unit recording Archives

Human Substantia Nigra Neurons Tracked Prior Reward and Faster Motivation

by GLOOM

MHD featured image for substantia nigra dopamine reward-history signals.

A 2026 iScience study recorded 27 substantia nigra neurons during deep-brain-stimulation surgery in 11 Parkinson’s disease patients and found that prior reward shaped both putative dopamine-neuron firing and the next reaction time: responses were faster after a +$10 outcome than after neutral or negative outcomes (0.916 s vs. 1.017 s, p = 0.0175).1 Research Highlights …

Prior Cocaine Use Disrupts Orbitofrontal Hidden-State Coding

by GLOOM

A 2026 eLife study recorded 3,881 lateral orbitofrontal cortex units in rats and found that prior cocaine use made the OFC over-distinguish task positions that controls treated as functionally equivalent. The headline result was not gross task failure: cocaine-experienced rats still performed the odor task, but their OFC ensembles showed higher S1-vs.-S2 decoding than sucrose …