Fig. 2

Cortical and sub-cortical targets of DCN-innervated intralaminar neurons. a Stereotaxic injection scheme in P18 mice. b The primary AAV8-WGAcre infection site is confined to medial (Med) and interposed cerebellar nuclei (IntA, IntP). Scale bar: 500 µm. c Overview (left) and enlargement (right) of ILN in mice four weeks post-infection. Cells expressing mCherry (orange) are observed in parafascicular nucleus (PaF) and centrolateral nucleus (CL), as well as in a few cells of the posterior thalamic nucleus (Po). Individual cell bodies are displayed in the inset derived from the area marked by a dashed square. Scale bars are 500, 200, and 20 μm as indicated. d Negative control section from a mouse injected with AAV8-WGAcre alone (left), and a mouse injected with AAV2-DiO-mCherry alone (right). Scale bar: 500 µm. e ILN neurons transneuronally labeled from the DCN project densely to several cortical and striatal areas contralateral (left and middle), but not ipsilateral (right) to the DCN injection site. Cortical areas marked are frontal association cortex (FrA), cingulate cortex, area 24a (A24), primary motor cortex (M1), upper lip (S1ULp) and barrel field (S1BF) of primary somatosensory cortex, secondary somatosensory cortex (S2), auditory cortex (AuD) and visual cortex (V). Scale bar: 1 mm. f Coverage by ILN-derived axons (labeled as in a) in cortical areas and in dorsal striatum (quantified from 14 sections derived from N = 3 mice for each area, mean ± SEM). g Simplified cartoon illustrating striatal medium spiny neurons (MSNs), cholinergic interneurons (ChAT) and thalamic axons (orange) emerging from ILN. h, Axons derived from ILN and transneuronally marked from DCN form mCherry- and vGluT2-positive contacts onto PENK-positive (D2R-positive MSNs) and ChAT-positive interneurons in the dorsal striatum. Dashed circles highlight the somata of the cells. The right panels show enlargements of the vGluT2-positive contacts. Scale bars are 30, 10, and 5 μm as indicated. All experiments in this figure were replicated in five animals. Anatomical annotations: APT anterior pretectal nucleus; fr fasciculus retroflexus; LDDM laterodorsal thalamic nucleus, dorsomed; LDVL laterodorsal thalamic nucleus, ventrolateral; LHb lateral habenular nucleus; MD mediodorsal thalamic nucleus; ST striatum; VL ventrolateral thalamic nucleus