PT  - JOURNAL ARTICLE
AU  - Chloé Alexandre
AU  - Daniela Popa
AU  - Véronique Fabre
AU  - Saoussen Bouali
AU  - Patrice Venault
AU  - Klaus-Peter Lesch
AU  - Michel Hamon
AU  - Joëlle Adrien
TI  - Early Life Blockade of 5-Hydroxytryptamine 1A Receptors Normalizes Sleep and Depression-Like Behavior in Adult Knock-Out Mice Lacking the Serotonin Transporter
AID  - 10.1523/JNEUROSCI.5156-05.2006
DP  - 2006 May 17
TA  - The Journal of Neuroscience
PG  - 5554--5564
VI  - 26
IP  - 20
4099  - http://www.jneurosci.org/content/26/20/5554.short
4100  - http://www.jneurosci.org/content/26/20/5554.full
SO  - J. Neurosci.2006 May 17; 26
AB  - In serotonin transporter knock-out (5-HTT−/−) mice, extracellular serotonin (5-HT) levels are markedly elevated in the brain, and rapid eye movement sleep (REMS) is enhanced compared with wild-type mice. We hypothesized that such sleep impairment at adulthood results from excessive serotonergic tone during early life. Thus, we assessed whether neonatal treatment with drugs capable of limiting the impact of 5-HT on the brain could normalize sleep patterns in 5-HTT−/− mutants. We found that treatments initiated at postnatal day 5 and continued for 2 weeks with the 5-HT synthesis inhibitor para-chlorophenylalanine, or for 4 weeks with the 5-HT1A receptor (5-HT1AR) antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide (WAY 100635), induced total or partial recovery of REMS, respectively, in 5-HTT−/− mutants. Early life treatment with WAY 100635 also reversed the depression-like behavior otherwise observed in these mutants. Possible adaptive changes in 5-HT1AR after neonatal treatment with WAY 100635 were investigated by measuring 5-HT1A binding sites and 5-HT1A mRNA in various REMS- and/or depression-related brain areas, as well as 5-HT1AR-mediated hypothermia and inhibition of neuronal firing in the dorsal raphe nucleus. None of these characteristics were modified in parallel with REMS recovery, suggesting that 5-HT1ARs involved in wild-type phenotype rescue in 5-HTT−/− mutants are located in other brain areas or in 5-HT1AR-unrelated circuits where they could be transiently expressed during development. The reversal of sleep alterations and depression-like behavior after early life blockade of 5-HT1AR in 5-HTT−/− mutants might open new perspectives regarding preventive care of sleep and mood disorders resulting from serotonin transporter impairments during development.