Decreased expression of the c-Fos, but not Jun B, transcription factor in the auditory pathway of the rat after repetitive acoustic stimulation.
Between the 21st and 34th postnatal days, male rats received an acoustic stimulus every second day, and the expression of c-Fos and Jun B proteins was compared with rats that received only a single acoustic stimulus at postnatal day 34. For acoustic stimulation, 8-kHz pure-tone bursts (100 ms duration at a rate of 6.3 Hz) were applied for 5 min. The numbers of neurons immunoreactive to c-Fos and Jun B were studied 2 h after the last or acute stimulus, respectively, in the ventral cochlear nucleus (VCN), dorsal cochlear nucleus (DCN) and inferior colliculus (IC). Compared with the single stimulus, repetitive stimulation significantly reduced the number of c-Fos labeled neurons in the VCN by 51%, in the DCN by 75% and in the IC by 48%. In contrast to c-Fos, repetitive stimulation did not significantly lower the number of Jun-B-expressing neurons. These findings indicate that independent intraneuronal pathways terminate on the induction of c-Fos- and Jun-B-expressing genes during the juvenile maturation of the acoustic pathway and that chronic exposure of acoustic events alters the program of intraneuronal gene expression by reducing transcriptional activities with subsequent stabilization at the genetic level.
Keilmann
A
A
Department of Otolaryngology, University of Heidelberg, Mannheim, Germany.
Herdegen
T
T
D000161:Acoustic Stimulation; D000818:Animals; D001306:Auditory Pathways / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D016762:Genes, fos; D016758:Genes, jun; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun