title: Early social isolation provokes electrophysiological and structural changes in cutaneous sensory nerves of adult male rats.
abstract: Sensory and social deprivation from the mother and littermates during early life disturbs the development of the central nervous system, but little is known about its effect on the development of the peripheral nervous system. To assess peripheral effects of early isolation, male rat pups were reared artificially in complete social isolation (AR); reared artificially with two same-age conspecifics (AR-Social); or reared by their mothers and with littermates (MR). As adults, the electrophysiological properties of the sensory sural (SU) nerve were recorded. We found that the amplitude and normalized area (with respect to body weight) of the compound action potential (CAP) response provoked by single electrical pulses of graded intensity in the SU nerves of AR animals were shorter than the CAP recorded in SU nerves from MR and AR-Social animals. The slope of the stimulus-response curve of AR SU nerves was smaller than that of the other nerves. The histological characterization of axons in the SU nerves was made and showed that the myelin thickness of axons in AR SU nerves was significant lower (2-7µm) than that of the axons in the other nerves. Furthermore, the area and axon diameter of SU nerves of both AR and AR-Social animals were significant lower than in MR animals. This is the first report to show that maternal and littermate deprivation by AR disturbs the development of the myelination and electrophysiological properties of axons in the SU nerve; the replacement of social cues prevents most of the effects.
authors.affiliation: Department of Biology, FES Iztacala, UNAM. Av. de los Barrios 1 Col. Los Reyes Iztacala, Tlanepantla de Baz, Estado de México, CP 54090, México.
authors.forename: Bertha
authors.initials: B
authors.lastname: Segura
authors.forename: Angel I
authors.initials: AI
authors.lastname: Melo
authors.forename: Alison S
authors.initials: AS
authors.lastname: Fleming
authors.forename: Maria Eugenia
authors.initials: ME
authors.lastname: Mendoza-Garrido
authors.forename: Margarita
authors.initials: M
authors.lastname: González del Pliego
authors.forename: Elsa L
authors.initials: EL
authors.lastname: Aguirre-Benitez
authors.forename: Jesús
authors.initials: J
authors.lastname: Hernández-Falcón
authors.forename: Ismael
authors.initials: I
authors.lastname: Jiménez-Estrada
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000473:pathology / Q000502:physiology; D001835:Body Weight; D004558:Electric Stimulation; D008297:Male; D008426:Maternal Deprivation; D008839:Microelectrodes; D009186:Myelin Sheath / Q000473:pathology / Q000502:physiology; D011897:Random Allocation; D017208:Rats, Wistar; D012934:Social Isolation; D013497:Sural Nerve / Q000254:growth & development / Q000473:pathology* / Q000503:physiopathology*; D046509:Tissue Culture Techniques
keywords: artificial rearing; electrophysiology; maternal separation; myelin; sensory sural nerves