Dynamic alterations of serotonergic metabolism and receptors during social isolation of low- and high-active mice.
Alterations induced by social isolation (1 day to 18 weeks) in low- and high-active mice (LAM and HAM) were studied in respect to serotonin metabolism, [3H]-8-OH-DPAT binding of presynaptic (midbrain), postsynaptic (hippocampus) 5-HT1A receptors and [3H]-ketanserin binding of cortical 5-HT2A receptors. Individual housing of mice was associated with reduction of serotonin metabolism, depending on isolation time and brain structure. Whereas a transient decrease in the striatum and cortex was detected between 1 week and 6 weeks, reduction of cerebellar and hippocampal serotonin metabolism was found later (12-18 weeks). Serotonergic systems of HAM were found to be more reactive to environmental disturbances, and their serotonin metabolism was more affected by social isolation. Isolation-induced upregulation of cortical 5-HT2A receptors was measured only in HAM. Densities of postsynaptic 5-HT1A receptors in the hippocampus did differ either in grouped or isolated mice. However, there were significant differences in hippocampal 5-HT1A receptor affinity, especially between 1 day and 3 weeks. Transient downregulation of presynaptic 5-HT1A receptors in the midbrain was found in isolated mice between 3 and 6 weeks. These results are discussed in terms of interactions between serotonergic alterations and isolation-induced aggression.
Rilke
O
O
AG Neurobiologie, Klinik für Psychiatrie, TU Dresden, Germany.
Freier
D
D
Jähkel
M
M
Oehler
J
J
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000493:pharmacokinetics; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007650:Ketanserin / Q000493:pharmacokinetics; D007700:Kinetics; D008297:Male; D008636:Mesencephalon / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000235:genetics* / Q000502:physiology*; D011985:Receptors, Serotonin / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000493:pharmacokinetics; D017366:Serotonin Receptor Agonists / Q000493:pharmacokinetics; D012934:Social Isolation
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D007650:Ketanserin