Fig. 9: ATN connections with hypothalamus, midbrain, and hindbrain.
From: Distinct subnetworks of the mouse anterior thalamic nuclei
a Projections from mammillary bodies to ATN. a1 A retrograde CTB injection in IAD labels neurons in MM median (MMme; MMme→IAD) (top). A PHAL anterograde tracer injection in the MMme (middle) labels the IAD (bottom) validating the connection. a2 CTB injection in AD labels LM neurons (MMl neurons labeled from injection leakage into AV). The LM→AD is validated with a PHAL LM injection that labels the AD. a3 A CTB AV injection labels MMl neurons. This MMl→AV connection is validated by an MMl AAV injection. a4 A CTB AM injection labels MMm neurons (MMm→AM), which is validated by an AAV MMm injection. b Schematic summarizing ATN, MM, and LM connectivity. c PHAL and AAV tracers in MMm and LM in the same brain show the bilateral LM→AD projections compared to the unilateral MMm→AM projection. d MMme PHAL injection shows bilateral MMme→IAD projections. e Cre-dependent TVA receptor mediated rabies tracing of AMv and AMd.medial neurons retrogradely label MMm validating MMm→AMd/AMv connections. Bar graph shows the quantification of retrogradely labeled cells in the MM versus LM following the injections. f AAV injection in the DTN (top), confirmed by strong projections to LM (middle), labels terminals in AD and AV (bottom). g AAV in the VTN (top), confirmed by the strong projections to MM (middle), labels terminals in AD and AV (bottom). h Validation of the DTN/VTN→AD/AV connections. CTB injection in AM/AD labels cells in VTN, while a FG AM/AV injection, confirmed by MM labeled cells, shows labels in DTN and LDT. i Double retrograde injections in AV (CTB, pink) and MM (CTB, green) show labeled cells in VTN (VTN→AV/MM) and in SUBv (SUBv→AV/MM). Note the labeled cells in MMl, which confirm AV injection ___location. Also, note the laminar specific arrangement of SUBv→AV and SUBv→MM projecting neurons. j Schematic of connections among ATN, DTN, and VTN. k Schematic showing generally segregated networks of head directionality/visual-spatial processing (peach) involving AD←LM↔DTN and theta rhythmicity (blue) involving AV←MM↔VTN. Direct connections shown in (f, g) suggest a more interconnected network rather than segregated circuits. See Supplementary Table 2 for structure abbreviations.
