Lateral Thalamic Eminence: A Novel Origin for mGluR1/Lot Cells

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Lot cells are a unique cell population in the rodent brain that circumscribe the lateral olfactory tract (LOT).
• They were previously believed to originate from the dorsal pallium (DP).

Purpose of the Study:

• To investigate the true origin of lot cells.
• To differentiate lot cells from Cajal-Retzius (CR) cells and identify their developmental sources.

Main Methods:

• Utilized Lhx2 null mice to assess the role of the dorsal pallium.
• Employed Wnt3a- and Dbx1-reporter mouse lines to trace cell origins.
• Combined in utero electroporation assays and histochemical characterization.

Main Results:

• Lhx2 null mice showed an increased number of mGluR1/lot cells in the piriform cortex, indicating a non-DP origin.
• mGluR1/lot cells were not generated in known CR cell sources (cortical hem, ventral pallium, septum).
• Lot cells were specifically identified as originating from the lateral thalamic eminence.

Conclusions:

• Most mGluR1/lot cells are prospective mitral cells migrating to the accessory olfactory bulb (OB).
• A minority of lot cells (mGluR1+, ΔNp73+) are CR cells migrating through the LOT.
• This study identifies a novel origin for lot cells in the lateral thalamic eminence.