Acoustic over-exposure triggers burst firing in dorsal cochlear nucleus fusiform cells

Autor: Martine Hamann, Charles H. Large, Ian D. Forsythe, Nadia Pilati
Rok vydání: 2012
Předmět:
Patch-Clamp Techniques
Time Factors
Voltage clamp
½ Fmax
half maximal frequency
N.S.
non significant
Membrane Potentials
Tinnitus
HVA
high voltage activated
chemistry.chemical_compound
0302 clinical medicine
0303 health sciences
Sensory Systems
medicine.anatomical_structure
Potassium Channels
Voltage-Gated
DCN
dorsal cochlear nucleus
DNQX
6
7-dinitroquinoxaline-2
3-dione
CNQX
ISI
inter-spike intervals
medicine.symptom
FCs
fusiform cells
Research Paper
Cochlear Nucleus
Dorsal cochlear nucleus
AOE
acoustic over-exposure
DL-AP5
DL-2-amino-5-phosphonopentanoic acid
Vm
membrane potential
SPL
sound pressure level
Fmax
maximal frequency
Biology
Cochlear nucleus
03 medical and health sciences
Bursting
Evoked Potentials
Auditory
Brain Stem
otorhinolaryngologic diseases
medicine
Animals
Patch clamp
Rats
Wistar
030304 developmental biology
CV
coefficient of variation
Auditory Threshold
ABR
auditory brainstem response
CNQX
6-cyano-7-nitroquinoxaline-2
3-dione
Rats
Cw
cartwheel cells
Disease Models
Animal
Auditory brainstem response
Acoustic Stimulation
Hearing Loss
Noise-Induced
chemistry
Potassium
ACSF
artificial cerebrospinal fluid
AP
action potential
Noise
Neuroscience
030217 neurology & neurosurgery
Zdroj: Hearing Research
ISSN: 0378-5955
DOI: 10.1016/j.heares.2011.10.008
Popis: Acoustic over-exposure (AOE) triggers deafness in animals and humans and provokes auditory nerve degeneration. Weeks after exposure there is an increase in the cellular excitability within the dorsal cochlear nucleus (DCN) and this is considered as a possible neural correlate of tinnitus. The origin of this DCN hyperactivity phenomenon is still unknown but it is associated with neurons lying within the fusiform cell layer. Here we investigated changes of excitability within identified fusiform cells following AOE. Wistar rats were exposed to a loud (110 dB SPL) single tone (14.8 kHz) for 4 h. Auditory brainstem response recordings performed 3–4 days after AOE showed that the hearing thresholds were significantly elevated by about 20–30 dB SPL for frequencies above 15 kHz. Control fusiform cells fired with a regular firing pattern as assessed by the coefficient of variation of the inter-spike interval distribution of 0.19 ± 0.11 (n = 5). Three to four days after AOE, 40% of fusiform cells exhibited irregular bursting discharge patterns (coefficient of variation of the inter-spike interval distribution of 1.8 ± 0.6, n = 5; p
Highlights ► Wistar rats were exposed to 15 kHz, 110 dB SPL (acoustic over exposure, AOE). ► AOE triggered hearing loss in rats for frequencies exceeding 15 kHz. ► AOE triggered bursts in dorsal cochlear nucleus fusiform cells. ► AOE reduced high voltage activated K+ currents in those cells.
Databáze: OpenAIRE
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