Charting the single cell transcriptional landscape governing visual imprinting

We investigated transcriptional changes associated with memory formation in the avian brain by performing single-nucleus RNA sequencing of the intermediate medial mesopallium (IMM) in imprinted and untrained chicks. Trained, good learner chicks contrasted versus untrained chicks. In short, Twenty-four hours post-hatching, chicks were exposed to a rotating red cuboid light while positioned in a running wheel, followed by a preference test conducted ten minutes later to assess memory strength. Individuals scoring above 80—indicating a strong preference for the training stimulus over an alternative—were classified as good learners. After an additional 24 hours, these chicks were sacrificed and their left intermediate medial mesopallium (IMM) was dissected for analysis. Untrained, stimulus-naive chicks served as controls.