The Serotonergic System: Its Role in Pathogenesis and Early Developmental Treatment of Autism

D Zafeiriou,E Vargiami,A Ververi

doi:10.2174/157015909788848848

D Zafeiriou, E Vargiami + Show 1 more

Open Access

https://doi.org/10.2174/157015909788848848

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Abstract

Autism is a severe childhood disorder already presenting in the first 3 years of life and, therefore, strongly correlated with neurodevelopmental alterations in prenatal, as well as postnatal period. Neurotransmitters hold a pivotal role in development by providing the stimulation needed for synapses and neuronal networks to be formed during the critical period of neuroplasticity. Aberrations of the serotonergic system modify key processes in the developing brain and are strongly implicated in the pathophysiology of developmental disorders. Evidence for the role of serotonin in autism emerges from neuropathological, imaging and genetic studies. Due to its developmental arrest, autism requires early intervention that would, among others, target the disrupted serotonergic system and utilize brain plasticity to elicit clinically important brain changes in children.

Highlights

Autism is a severe childhood disorder presenting in the first 3 years of life and affecting 1.3/1000 individuals [41]
Autism is a disorder of developmental arrest, rather than a progressive process and requires, the earliest possible intervention
According to positron emission tomography (PET) studies, children aged 2 to 5 years normally undergo a period of increased serotonin synthesis capacity (200% of adult values), followed by a decline toward adult values between the ages of 5 and 14 years

Summary

INTRODUCTION

Autism is a severe childhood disorder presenting in the first 3 years of life and affecting 1.3/1000 individuals [41]. Serotonin holds an important role in dendritic development, including overall dendritic length, spine formation and branching in both hippocampus and cortex [103]. Animal studies have identified a serotonin depletion model of neonatal mice that mimics neurochemical and structural changes in cortex and displays a behavioral phenotype consistent with autism [14,47]. As far as it concerns humans, it has been reported that the severity of at least one specific behavioral dimension in autism (repetitive behaviors) parallels the sensitivity of the 5HT1D receptor [48]. Neuroimaging, neuropathological and genetic studies have added to the evidence for the large-scale involvement of serotonin in pathogenesis and, in treatment of autism

NEUROIMAGING STUDIES

NEUROPATHOLOGICAL STUDIES

GENETIC STUDIES

NEURODEVELOPMENTAL INTERVENTION

Findings

CONCLUSION