Effect of maternal deprivation on N-acetyltransferase activity rhythm in blinded rat pups.
It has been reported that the rhythms of infant rats synchronize with the mother's rhythm until the light-dark cycle comes and has strong effects on their endogenous clocks. We found that periodic maternal deprivation (PMD) was able to cause a phase shift of serotonin N-acetyltransferase (NAT) in neonatal blinded rat pups. PMD in which contact with the mother was allowed for only 4 h caused a phase shift of NAT rhythm, irrespective of the timing of contact with the mother in a day. Acute single mother deprivation caused an excess of NAT activity for more hours than usual and contact with the mother prevented such an excessive response. Mother deprivation may act as a cold stress, since artificial warming of pups gave the same results as contact with the mother. When the pups were artificially warmed by a heater during a 1-week deprivation period, a flat 24-h pattern of NAT was observed. The mechanism causing a phase shift of NAT activity rhythm of rat pups may be complicated.
Katoh
Y
Y
Department of Psychiatry and Behavioral Science, School of Medicine, Tokai University, Kanagawa, Japan.
Takeuchi
Y
Y
Yamazaki
K
K
Takahashi
K
K
D000818:Animals; D000831:Animals, Newborn; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D001766:Blindness / Q000201:enzymology* / Q000523:psychology; D001831:Body Temperature / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D008297:Male; D008426:Maternal Deprivation; D051381:Rats; D017208:Rats, Wistar; D013391:Sucking Behavior / Q000502:physiology; D013696:Temperature
D001191:Arylamine N-Acetyltransferase