Perinatal exposure to 5-metoxytryptamine, behavioural-stress reactivity and functional response of 5-HT1A receptors in the adolescent rat

Abstract

Serotonin is involved in a wide range of physiological and patho-physiological mechanisms. In particular, 5-HT1A receptors are proposed to mediate stress-adaptation. The aim of this research was to investigate in adolescent rats: first, the consequences of perinatal exposure to 5-metoxytryptamine (5MT), a 5-HT1/5-HT2 serotonergic agonist, on behavioural-stress reactivity in elevated plus maze, open field and forced swim tests; secondly, whether the behavioural effects induced by perinatal exposure to 5MT on open field and forced swim tests were affected by the selective 5-HT1A receptor agonist LY 228729, a compound able to elicit a characteristic set of motor behaviours on these experimental models, and by the co-administration of the selective and silent 5-HT1A antagonist WAY 100635. Results indicate that a single daily injection of 5MT to, pregnant dams from gestational days 12 to 21 (1mg/kg s.c.), and to the pups from postnatal days 2 to 18 (0.5mg kg s.c.), induce in the adolescent rat offspring: an increase in the percentage of entries and time spent on the open arms in the elevated plus maze; a reduction in locomotor activity and rearing frequency, and an increase in the time spent on the central areas in the open field test; a decrease in immobility and an increase in swimming in the forced swim test. Acute administration of LY 228729 (1.5mg/kg s.c.) strongly decreases rearing frequency and increases peripheral activity in the open field test, and decreases immobility and increases swimming in the forced swim test both in perinatally vehicle and 5MT-exposed offspring. Co-administration of WAY 100635 (0.25mg/kg s.c.) abolishes the effects exerted by LY 228729. These results suggest that, in the adolescent rat, perinatal exposure to 5MT enhances the stress-related adaptive behavioural responses, presumably through a predominant action on presynaptic 5-HT1A receptors and does not deteriorate the functional response of 5-HT1A receptors to selective agonist and antagonist compounds.

Prenatal exposure to integerrimine N‐oxide enriched butanolic residue from Senecio brasiliensis affects behavior and striatal neurotransmitter levels of rats in adulthood

“…Serotonin exerts its influence in a number of behavioral and physiological processes in adult mammals (Cannizzaro et al, 2008; Donovan and Tecott, 2013). Some animal studies have demonstrated that interference in the serotoninergic system during pregnancy produces adverse neuroanatomic effects in the offspring, including reduced numbers of β‐adrenergic and serotoninergic receptors and abnormalities in brain serotonin receptor binding.…”

Neurobehavioral, reflexological and physical development of Wistar rat offspring exposed to ayahuasca during pregnancy and lactation

“…Serotonin exerts its influence in a number of behavioral and physiological processes in adult mammals (Cannizzaro et al, 2008;Lauder et al, 1988;Lisboa et al, 2007). Some animal researches have shown that affecting the serotoninergic system during pregnancy produce adverse neuroanatomic effects in the offspring, including reduced numbers of β-adrenergic and serotonin receptors and abnormalities in brain serotonin receptor binding.…”

“…Some animal researches have shown that affecting the serotoninergic system during pregnancy produce adverse neuroanatomic effects in the offspring, including reduced numbers of β-adrenergic and serotonin receptors and abnormalities in brain serotonin receptor binding. During embryogenesis, serotonin regulates axon growth, synaptogenesis, the development of γ-aminobutyric acid (GABA) and monoamine systems and is involved in cell migration (Cannizzaro et al, 2008;Lauder et al, 2000;Lisboa et al, 2007). One of the most abundant subtype receptors expressed in the mammalian brain is the 5-HT1A.…”

“…One of the most abundant subtype receptors expressed in the mammalian brain is the 5-HT1A. Dysregulation of 5-HT1A receptors has been implicated in changes of emotional state (Cannizzaro et al, 2008). In spite of DMT has low to moderate affinity for the 5-HT1A (a receptor related to anxiolytic properties when stimulated), possibly this mechanism influenced the effects observed in the elevated plus maze test.…”

The effects of prenatal stress on expression of p38 MAPK in offspring hippocampus

“…Numerous studies show that stressors acting upon the organism during pregnancy can have distinct and long lasting effects on the offspring. Prenatally stressed offspring may exhibit alterations in brain morphology and behavior (Pivina et al, 2007; Lee et al, 2007), increased emotional reactivity (Bosch et al, 2007; Cannizzaro et al, 2008) and altered regulation of the hypothalamic–pituitary–adrenal (HPA) axis (Weinberg et al, 2008). It was reported hyperactivity of HPA axis in offspring induced by prenatal stress (PNS) was related to the high levels of maternal corticosterone secretion during restraint stress (Maccari et al, 2003).…”