title: Neonatal tactile stimulation enhances spatial working memory, prefrontal long-term potentiation, and D1 receptor activation in adult rats.
abstract: Environmental stimuli during neonatal periods play an important role in the development of cognitive function. In this study, we examined the long-term effects of neonatal tactile stimulation (TS) on spatial working memory (SWM) and related mechanisms. We also investigated whether TS-induced effects could be counteracted by repeated short periods of maternal separation (MS). Wistar rat pups submitted to TS were handled and marked transiently per day during postnatal days 2-9 or 10-17. TS/MS pups were stimulated in the same way as TS pups and then individually separated from their mother for 1h/day. Their nontactile stimulated (NTS) siblings served as controls. In adulthood, TS and TS/MS rats showed better performance in two versions of the delayed alternation task and superior in vivo long-term potentiation of the hippocampo-prefrontal cortical pathway when compared with controls. Furthermore, there were more doses of A77636 (a selective dopamine D1 agonist) to significantly improve SWM performance in TS and TS/MS rats than in NTS rats, suggesting that activation of prefrontal D1 receptors in TS and TS/MS rats is more optimal for SWM function than in NTS rats. MS did not counteract TS-induced effects because no significant difference was found between TS/MS and TS animals. These data indicate that in early life, external tactile stimulation leads to long-term facilitative effects in SWM-related neural function.
authors: Division of Brain and Behavior, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 Jiaochang East Road, Kunming, Yunnan 650223, China.
authors: Ming
authors: M
authors: Zhang
authors: Jing-Xia
authors: JX
authors: Cai
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives / Q000494:pharmacology; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001578:Benzopyrans / Q000494:pharmacology; D001835:Body Weight; D004193:Discrimination Learning / Q000187:drug effects / Q000502:physiology; D018491:Dopamine Agonists / Q000494:pharmacology; D004777:Environment; D005260:Female; D006185:Habituation, Psychophysiologic / Q000187:drug effects / Q000502:physiology; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008426:Maternal Deprivation; D008570:Memory, Short-Term / Q000187:drug effects / Q000502:physiology*; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D017397:Prefrontal Cortex / Q000254:growth & development / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000819:agonists / Q000502:physiology*; D013028:Space Perception / Q000187:drug effects / Q000502:physiology*; D014110:Touch / Q000502:physiology*
chemical_list: D001578:Benzopyrans; D018491:Dopamine Agonists; D017447:Receptors, Dopamine D1; C079415:A 77636; D000218:Adamantane