Advanced search
Start date
Betweenand

Changes during the development of ionic currents and neurotransmission of auditory neurons: effects of the acoustic environment

Grant number: 19/13458-1
Support type:Regular Research Grants
Duration: November 01, 2019 - October 31, 2021
Field of knowledge:Biological Sciences - Biophysics - Cellular Biophysics
Principal Investigator:Ricardo Mauricio Xavier Leão
Grantee:Ricardo Mauricio Xavier Leão
Home Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
Assoc. researchers:Alexandra Olimpio Siqueira Cunha

Abstract

The world is increasingly a place where humans are exposed to high-intensity sounds. The most common problems associated with exposure to high noise levels are hearing loss, tinnitus (ringing in the ears)) and hyperacusis. Not all people exposed to high-intensity sounds develop tinnitus, which is also observed in experimental animals. The dorsal cochlear nucleus (DCN) is a region that has been shown to be crucial for the development of tinnitus. Tinnitus symptoms in animals begin with hyperactivity of the fusiform neurons. Thus, to understand what governs the expression of the ion channels of the fusiform neurons and how their biophysical properties determine the neuronal phenotypes, it is necessary to understand how their excitability can be altered by environmental conditions, which could explain the susceptibility to a tinnitus of different individuals. Fusiform cells exist in one of two qualitatively different intrinsic states: a resting state and a spontaneously firing state. These states are determined by the heterogeneous expression of subliminal ionic currents. We do not know the physiological importance of this heterogeneity of firing mode. Additionally, we do not know whether this heterogeneity is innate, arising before the hearing onset, or the result of sensory activity. Thus, the present study aims to determine the role of the variation of the different ionic currents and their biophysical properties of fusiform cells during development and to establish the influence of auditory sensorial stimulation in the development of these currents. (AU)