RT Journal Article
SR Electronic
T1 Distribution of Midbrain Cholinergic Axons in the Thalamus
JF eneuro
JO eNeuro
FD Society for Neuroscience
SP ENEURO.0454-19.2019
DO 10.1523/ENEURO.0454-19.2019
VO 7
IS 1
A1 Huerta-Ocampo, Icnelia
A1 Hacioglu-Bay, Husniye
A1 Dautan, Daniel
A1 Mena-Segovia, Juan
YR 2020
UL http://www.eneuro.org/content/7/1/ENEURO.0454-19.2019.abstract
AB Cholinergic transmission is essential for adaptive behavior and has been suggested to play a central role in the modulation of brain states by means of the modulation of thalamic neurons. Midbrain cholinergic neurons from the pedunculopontine nucleus (PPN) and the laterodorsal tegmental nucleus (LDT) provide dense innervation of the thalamus, but a detailed connectivity mapping is missing. Using conditional tracing of midbrain cholinergic axons in the rat, together with a detailed segmentation of thalamic structures, we show that projections arising in PPN and LDT are topographically organized along the entire extent of the thalamus. PPN cholinergic neurons preferentially innervate thalamic relay structures, whereas LDT cholinergic neurons preferentially target thalamic limbic nuclei. Moreover, both PPN and LDT provide a dense innervation of the intralaminar thalamic nuclei. Notably, we observe a differential synaptic density that functionally dissociates between PPN and LDT innervation. Our results show that midbrain cholinergic neurons innervate virtually all thalamic structures and this innervation is functionally segregated.