Maternal deprivation regulates serotonin 1A and 2A receptors in the infant rat.
Several studies have demonstrated that 5-HT1A and 5-HT2A receptors are altered in rat brain following chronic stress. While this is true in the adult animal, this may be different in the developing animal, which has a limited corticosterone response to acute challenges between days 3 and 14 of life.


METHODS
We investigated the effect of maternal deprivation on 5-HT2A and 5-HT1A receptor mRNA levels in the developing brain. In situ hybridization was used to quantify gene expression in rat pups at three ages: 6, 9, and 12 days old. In each age group, half were maternally deprived for 24 h and half were kept with their mothers. Maternally deprived animals showed elevated ACTH and corticosterone plasma levels when compared to NDEP animals, significantly elevated 5-HT1A mRNA levels in the CA1 hippocampal region and, significantly elevated 5-HT2A mRNA levels in the parietal cortex. No changes were observed in 5-HT1A or 5-HT-transporter mRNA levels in the dorsal raphe. Our results indicate that post-synaptic 5-HT receptors in the developing hippocampus and cortex are sensitive to maternal deprivation. Because hippocampal 5-HT1A gene expressions are known to decrease in the adult animal after chronic glucocorticoid elevation, this data also suggests that other mechanisms, perhaps central, predominate during development.
Vázquez
D M
DM
Endocrine Division, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA. dmvazq@umich.edu
López
J F
JF
Van Hoers
H
H
Watson
S J
SJ
Levine
S
S
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000367:Age Factors; D000818:Animals; D001933:Brain Stem / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D003345:Corticosterone / Q000097:blood; D005260:Female; D005625:Frontal Lobe / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D015870:Gene Expression / Q000502:physiology; D006624:Hippocampus / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D008426:Maternal Deprivation; D010296:Parietal Lobe / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000235:genetics* / Q000378:metabolism; D044263:Receptors, Serotonin, 5-HT1
D012333:RNA, Messenger; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone