title: Age-related changes in BDNF protein levels in human serum: differences between autism cases and normal controls.
abstract: Accumulating evidence suggests the possible association between the concentrations of serum brain-derived neurotrophic factor (BDNF) and psychiatric disease with impaired brain development. Yet the reasons remain unclear. We therefore investigated the characteristics of serum BDNF as well as its age-related changes in healthy controls in comparison to autism cases. BDNF was gradually released from platelets at 4 degrees C, reached a maximal concentration after around 24 h, and remained stable until 42 h. At room temperature, BDNF was found to be immediately degraded. Circadian changes, but not seasonal changes, were found in serum levels of BDNF existing as the mature form with a molecular mass of 14 kDa. In healthy controls, the serum BDNF concentration increased over the first several years, then slightly decreased after reaching the adult level. There were no sex differences between males and females. In the autism cases, mean levels were significantly lower in children 0-9 years old compared to teenagers or adults, or to age-matched healthy controls, indicating a delayed BDNF increase with development. In a separate study of adult rats, a circadian change in serum BDNF was found to be similar to that in the cortex, indicating a possible association with cortical functions.
authors.affiliation: Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan. katohsemba@inst-hsc.jp
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Katoh-Semba
authors.forename: Rie
authors.initials: R
authors.lastname: Wakako
authors.forename: Taku
authors.initials: T
authors.lastname: Komori
authors.forename: Hiroko
authors.initials: H
authors.lastname: Shigemi
authors.forename: Noriko
authors.initials: N
authors.lastname: Miyazaki
authors.forename: Hironori
authors.initials: H
authors.lastname: Ito
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kumagai
authors.forename: Masako
authors.initials: M
authors.lastname: Tsuzuki
authors.forename: Kenji
authors.initials: K
authors.lastname: Shigemi
authors.forename: Futoshi
authors.initials: F
authors.lastname: Yoshida
authors.forename: Atsuo
authors.initials: A
authors.lastname: Nakayama
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000375:Aging / Q000097:blood*; D000818:Animals; D001321:Autistic Disorder / Q000097:blood* / Q000503:physiopathology; D001792:Blood Platelets / Q000378:metabolism; D001921:Brain / Q000254:growth & development* / Q000378:metabolism* / Q000503:physiopathology; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood* / Q000737:chemistry; D002540:Cerebral Cortex / Q000254:growth & development / Q000378:metabolism / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D051381:Rats; D012621:Seasons; D017678:Sex Distribution; D013048:Specimen Handling; D013696:Temperature; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology