Neuropeptide Y in Rat Spiral Ganglion Neurons and Inner Hair Cells of Organ of Corti and Effects of a Nontraumatic Acoustic Stimulation

Autor(es)

Gomide, Vania C. ^[1] ; Laureano, Maura R. ^[1] ; Silveira, Gilcelio A. ^[1] ; Chadi, Gerson ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Neurol, Sch Med, BR-01246903 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: International Journal of Neuroscience; v. 119, n. 4, p. 508-530, 2009.
• Citações Web of Science: 3

Resumo

Neuropeptide Y (NPY) is an important neuromodulator found in central and peripheral neurons. NPY was investigated in the peripheral auditory pathway of conventional housed rats and after nontraumatic sound stimulation in order to localize the molecule and also to describe its response to sound stimulus. Rats from the stimulation experiment were housed in monitored sound-proofed rooms. Stimulated animals received sound stimuli (pure tone bursts of 8 kHz, 50 ms duration presented at a rate of 2 per second) at an intensity of 80 dB sound pressure level for 1 hr per day during 7 days. After euthanizing, rat cochleae were processed for one-color immunohistochemistry. The NPY immunoreactivity was detected in inner hair cells (IHC) and also in pillar and Deiters' cells of organ of Corti, and in the spiral ganglion putative type I (1,009 m3) and type II (225 m3) neurons. Outer hair cells (OHC) showed light immunoreaction product. Quantitative microdensitometry showed strong and moderate immunoreactions in IHC and spiral ganglion neurons, respectively, without differences among cochlear turns. One week of acoustic stimulation was not able to induce changes in the NPY immunoreactivity intensity in the IHC of cochlea. However, stimulated rats showed an overall increase in the number of putative type I and type II NPY immunoreactive spiral ganglion neurons with strong, moderate, and weak immunolabeling. Localization and responses of NPY to acoustic stimulus suggest an involvement of the neuropeptide in the neuromodulation of afferent transmission in the rat peripheral auditory pathway. (AU)

• Processo FAPESP: 99/01319-1 - Análise da regeneração da medula espinhal após enxertos de nervos ou inoculação de células de Schwann em presença do fator neurotrófico derivado de células gliais (GDNF)
• Beneficiário: Gerson Chadi
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 98/13122-5 - Efeito da ativação neuronal pela atividade física nas respostas tróficas e plásticas neuronais e gliais do sistema nervoso central lesado ou não de ratos: estudo imunohistoquímico combinado às análises estereológica e microdensitométrica quantitativas
• Beneficiário: Gerson Chadi
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 07/00491-3 - Análise do potencial das células de Schwann cultivadas e tratadas com o PEDF favorecem o trofismo de neurônios medulares in vitro a induzirem a regeneração e a recuperação motora de ratos submetidos ao trauma contuso da medula espinal pelo Impactor
• Beneficiário: Gerson Chadi
• Modalidade de apoio: Auxílio à Pesquisa - Regular