Transcriptome Analysis of Deafness: Intracellular Signal Transduction Signaling Pathways Regulate Neuroplastic Changes in the Auditory Cortex

Longitudinal Changes in BDNF and MMP-9 Protein Plasma Levels in Children after Cochlear Implantation

Congenitally deaf children who undergo cochlear implantation before 1 year of age develop their auditory skills faster than children who are implanted later. In this longitudinal study, a cohort of 59 implanted children were divided into two subgroups according to their ages at implantation-below or above 1 year old-and the plasma levels of matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and pro-BDNF were measured at 0, 8, and 18 months after cochlear implant activation, while auditory development was simultaneously evaluated using the LittlEARs Questionnaire (LEAQ). A control group consisted of 49 age-matched healthy children. We identified statistically higher BDNF levels at 0 months and at the 18-month follow-ups in the younger subgroup compared to the older one and lower LEAQ scores at 0 months in the younger subgroup. Between the subgroups, there were significant differences in the changes in BDNF levels from 0 to 8 months and in LEAQ scores from 0 to 18 months. The MMP-9 levels significantly decreased from 0 to 18 months and from 0 to 8 months in both subgroups and from 8 to 18 months only in the older one. For all measured protein concentrations, significant differences were identified between the older study subgroup and the age-matched control group.

A Time-Course Study of the Expression Level of Synaptic Plasticity-Associated Genes in Un-Lesioned Spinal Cord and Brain Areas in a Rat Model of Spinal Cord Injury: A Bioinformatic Approach

"Neuroplasticity" is often evoked to explain adaptation and compensation after acute lesions of the Central Nervous System (CNS). In this study, we investigated the modification of 80 genes involved in synaptic plasticity at different times (24 h, 8 and 45 days) from the traumatic spinal cord injury (SCI), adopting a bioinformatic analysis. mRNA expression levels were analyzed in the motor cortex, basal ganglia, cerebellum and in the spinal segments rostral and caudal to the lesion. The main results are: (i) a different gene expression regulation is observed in the Spinal Cord (SC) segments rostral and caudal to the lesion; (ii) long lasting changes in the SC includes the extracellular matrix (ECM) enzymes Timp1, transcription regulators (Egr, Nr4a1), second messenger associated proteins (Gna1, Ywhaq); (iii) long-lasting changes in the Motor Cortex includes transcription regulators (Cebpd), neurotransmitters/neuromodulators and receptors (Cnr1, Gria1, Nos1), growth factors and related receptors (Igf1, Ntf3, Ntrk2), second messenger associated proteins (Mapk1); long lasting changes in Basal Ganglia and Cerebellum include ECM protein (Reln), growth factors (Ngf, Bdnf), transcription regulators (Egr, Cebpd), neurotransmitter receptors (Grin2c). These data suggest the molecular mapping as a useful tool to investigate the brain and SC reorganization after SCI.