Thalamic reticular nucleus: anatomical evidence that cortico-reticular axons establish monosynaptic contact with reticulo-geniculate projection cells.

Cell bodies and dendrites of neurones in the thalamic reticular nucleus projecting to the dorsal lateral geniculate nucleus in adult albino rats, were labelled by retrograde transport of horseradish peroxidase (HRP). In the same animals the terminals of cortico-reticular axons were made identifiable by ipsilateral visual cortex ablation. Degenerating axon terminals established Gray type I synaptic contact with HRP-filled dendrites, indicating a monosynaptic connection between cortico-reticular and reticulo-geniculate projection cells.