Postnatal Development of Centrifugal Inputs to the Olfactory Bulb

COA (Cortical amygdalar area) MBA:631 projects to MOB (Main olfactory bulb) MBA:507 · Mouse

OB-projecting neurons in ipsilateral CoA were absent at birth and stayed absent or low during the first postnatal week. They increased abruptly between P6 and P9, reaching 47% of adult levels at P12, and outnumbered those in LEC and vCA1 at every age.

Fig. 5A-C, Fig. 6E-F

Made by an AI model reading the paper (claude-opus-5-5, extract@0.3.0); a second AI model (claude-opus-5-5) agrees.

CA1 (Field CA1) MBA:382 projects to MOB (Main olfactory bulb) MBA:507 · Mouse

Ipsilateral vCA1 contained no OB-projecting neurons at birth. Retrogradely labeled cells appeared from P9 onward but at P12 were only 15% of adult levels, indicating late development of this projection.

Fig. 5A-C, Fig. 6E-F

Made by an AI model reading the paper (claude-opus-5-5, extract@0.3.0); a second AI model (claude-opus-5-5) agrees.

AON (Anterior olfactory nucleus) MBA:159 projects to MOB (Main olfactory bulb) MBA:507 · Mouse

Retrograde AAV-CaMKIIa-mCherry and Retrobeads injected into the right OB labeled neurons in both ipsilateral and contralateral AON. These were present at low numbers from birth and increased with age, reaching 72% (ipsilateral) and 58% (contralateral) of adult levels by P12.

Fig. 1D, Fig. 3B-D, Fig. 6A-B

Made by an AI model reading the paper (claude-opus-5-5, extract@0.3.0); a second AI model (claude-opus-5-5) agrees.

NLOT (Nucleus of the lateral olfactory tract) MBA:619 projects to MOB (Main olfactory bulb) MBA:507 · Mouse

OB injections of retrograde tracers labeled neurons in ipsilateral nLOT from birth, while contralateral nLOT labeling was sparser and reliably detected only from P6. At P12, counts were 55% (ipsilateral) and 44% (contralateral) of adult levels.

Fig. 1D, Fig. 3B-D, Fig. 6A-B

Made by an AI model reading the paper (claude-opus-5-5, extract@0.3.0); a second AI model (claude-opus-5-5) agrees.

OT (Olfactory tubercle) MBA:754 projects to MOB (Main olfactory bulb) MBA:507 · Mouse

No retrogradely labeled OB-projecting neurons were found in the olfactory tubercle after retrograde AAV injection into the OB.

Results, section 1

Made by an AI model reading the paper (claude-opus-5-5, extract@0.3.0); a second AI model (claude-opus-5-5) agrees.

PIR (Piriform area) MBA:961 projects to MOB (Main olfactory bulb) MBA:507 · Mouse

Retrograde labeling from the OB marked neurons in anterior, intermediate and posterior ipsilateral PIR from birth, with an anterior-to-posterior gradient favoring anterior PIR. Counts rose with age; at P12 they were 77%, 62% and 39% of adult levels for aPIR, iPIR and pPIR respectively.

Fig. 4A-C, Fig. 6C-D

Made by an AI model reading the paper (claude-opus-5-5, extract@0.3.0); a second AI model (claude-opus-5-5) agrees.

ENTl (Entorhinal area, lateral part) MBA:918 projects to MOB (Main olfactory bulb) MBA:507 · Mouse

After retrograde tracer injection into the OB, very few ipsilateral LEC neurons were labeled at birth. Labeling rose suddenly from P6 to P9 and reached 37% of adult levels by P12.

Fig. 5A-C, Fig. 6E-F

Made by an AI model reading the paper (claude-opus-5-5, extract@0.3.0); a second AI model (claude-opus-5-5) agrees.