摘要
The laterodorsal tegmentum(LDT) is a brain structure involved in distinct behaviors including arousal,reward, and innate fear. How environmental stimuli and top-down control from high-order sensory and limbic cortical areas converge and coordinate in this region to modulate diverse behavioral outputs remains unclear.Using a modified rabies virus, we applied monosynaptic retrograde tracing to the whole brain to examine the LDT cell type specific upstream nuclei. The LDT received very strong midbrain and hindbrain afferents and moderate cortical and hypothalamic innervation but weak connections to the thalamus. The main projection neurons from cortical areas were restricted to the limbic lobe, including the ventral orbital cortex(VO), prelimbic, and cingulate cortices. Although different cell populations received qualitatively similar inputs, primarily via afferents from the periaqueductal gray area, superior colliculus, and the LDT itself, parvalbumin-positive(PV?) GABAergic cells received preferential projections from local LDT neurons.With regard to the different subtypes of GABAergic cells, aconsiderable number of nuclei, including those of the ventral tegmental area, central amygdaloid nucleus, and VO, made significantly greater inputs to somatostatinpositive cells than to PV?cells. Diverse inputs to the LDT on a system-wide level were revealed.
The laterodorsal tegmentum(LDT) is a brain structure involved in distinct behaviors including arousal,reward, and innate fear. How environmental stimuli and top-down control from high-order sensory and limbic cortical areas converge and coordinate in this region to modulate diverse behavioral outputs remains unclear.Using a modified rabies virus, we applied monosynaptic retrograde tracing to the whole brain to examine the LDT cell type specific upstream nuclei. The LDT received very strong midbrain and hindbrain afferents and moderate cortical and hypothalamic innervation but weak connections to the thalamus. The main projection neurons from cortical areas were restricted to the limbic lobe, including the ventral orbital cortex(VO), prelimbic, and cingulate cortices. Although different cell populations received qualitatively similar inputs, primarily via afferents from the periaqueductal gray area, superior colliculus, and the LDT itself, parvalbumin-positive(PV+) GABAergic cells received preferential projections from local LDT neurons.With regard to the different subtypes of GABAergic cells, aconsiderable number of nuclei, including those of the ventral tegmental area, central amygdaloid nucleus, and VO, made significantly greater inputs to somatostatinpositive cells than to PV+cells. Diverse inputs to the LDT on a system-wide level were revealed.
基金
supported by grants from the National Natural Science Foundation of China (31671100, 31471022, 31622027, 31490592, 81527901, and 81521062)
Zhejiang Provincial Natural Science Foundation, China (LR18H090001)
the Program for Introducing Talents in Disciplines to Universities
the Fundamental Research Funds for the Central Universities, China (2017YFA7002, and 2019QNA5001)
