Suckling dysfunction caused by defects in the olfactory system in genetic arhinencephaly mice

Area of Science:

• Neuroscience
• Developmental Biology
• Sensory Systems

Background:

• Newborn mice locate nipples for suckling, but the primary sensory system involved remains debated.
• Olfactory and tactile systems are considered key candidates for nipple localization in neonatal mice.

Purpose of the Study:

• To investigate the roles of the olfactory and trigeminal-whisker sensory systems in nipple-searching behavior and suckling in mouse newborns.
• To determine if the trigeminal-whisker system can compensate for olfactory deficits in neonatal mice.

Main Methods:

• Utilized genetic arhinencephaly mouse embryos (Pdn/Pdn) with known olfactory system defects.
• Assessed nipple-searching behavior and suckling success in Pdn/Pdn newborns.
• Examined the integrity of the olfactory and trigeminal-whisker systems in Pdn/Pdn models.

Main Results:

• Pdn/Pdn newborns exhibited complete developmental failure of olfactory nerve projections and olfactory bulb architecture.
• The trigeminal-whisker sensory system was found to be intact in Pdn/Pdn mice.
• Pdn/Pdn newborns displayed significant dysfunction in nipple-searching behavior and failed to suckle, leading to mortality within 24 hours.

Conclusions:

• The olfactory system is essential for successful nipple-searching behavior and suckling in mouse newborns.
• The trigeminal-whisker sensory system cannot compensate for the absence of olfactory input in this critical neonatal survival behavior.