Lysophosphatidylcholine induces delayed myelination in the juvenile ventral hippocampus and behavioral alterations in...

Area of Science:

• Neuroscience
• Developmental Psychology
• Neuroimmunology

Background:

• Maternal infections or polyinosinic-polycytidilic acid (poly(I:C)) injections induce behavioral alterations in offspring, including deficits in prepulse inhibition.
• Previous studies linked poly(I:C) exposure to delayed hippocampal myelination during early postnatal development.
• The long-term behavioral consequences of transiently delayed myelination in the juvenile hippocampus remain unclear.

Purpose of the Study:

• To investigate if a temporary delay in hippocampal myelination during the juvenile period leads to abnormal behaviors in adulthood.
• To establish a rat model for studying the impact of early myelination timing on sensorimotor and emotional functions.

Main Methods:

• Lysophosphatidylcholine (LPC), a demyelinating agent, was injected into the ventral hippocampus of 10-day-old rats.
• Myelination levels were assessed at postnatal day 16 and in adulthood.
• Behavioral tests, including prepulse inhibition, methamphetamine-induced hyperactivity, and anxiety-related behaviors, were performed on LPC-treated and control rats.

Main Results:

• LPC treatment induced hypomyelination at postnatal day 16, which normalized by adulthood.
• No significant disturbances in neuronal arrays or morphology were observed.
• LPC-treated rats exhibited deficits in prepulse inhibition, motor hyperactivity, and anxiety-related behaviors, mirroring findings in maternal infection models.

Conclusions:

• The timing of myelination in the early postnatal hippocampus is critical for the normal development of sensorimotor and emotional functions.
• The LPC-induced rat model, despite lacking gross anatomical defects, is a valuable tool for studying psychotic disorders.
• Transient hypomyelination during a specific developmental window can lead to lasting behavioral abnormalities.