Effects of early weaning on anxiety and prefrontal cortical and hippocampal myelination in male and female Wistar rats.
We investigated developmental changes in myelin formation in the prefrontal cortex and the hippocampus, and behavioral effects of early weaning in Wistar rats. Early-weaned rats showed decreased numbers of open-arm entries in an elevated plus-maze in both sexes at 4 weeks old; this effect persisted in males, but ceased in females after this age. Expression of myelin basic protein (MBP) showed both age-dependent increases and sex differences; 4-week-old males exhibited higher MBP levels in the hippocampus, whereas 7-week-old males showed lower MBP levels in the prefrontal cortex compared to females of the same age. There was a tendency for group differences from weaning for the 21.5-kDa isoform in the prefrontal cortex. Although these results suggest that male rats are more vulnerable than females to early-weaning effects on anxiety-related behaviors, further detailed analysis is needed to clarify the functional relationship between myelination and anxiety-related behaviors.
Kodama
Yuka
Y
Laboratory of Veterinary Ethology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-8657 Tokyo, Japan.
Kikusui
Takefumi
T
Takeuchi
Yukari
Y
Mori
Yuji
Y
D000818:Animals; D001007:Anxiety / Q000378:metabolism / Q000523:psychology*; D015153:Blotting, Western; D005260:Female; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism*; D008297:Male; D018782:Maze Learning / Q000502:physiology; D004676:Myelin Basic Protein / Q000378:metabolism; D009186:Myelin Sheath / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000166:cytology* / Q000378:metabolism*; D020033:Protein Isoforms; D051381:Rats; D017208:Rats, Wistar; D014886:Weaning
D004676:Myelin Basic Protein; D020033:Protein Isoforms