PMID- 18710637
OWN - NLM
STAT- MEDLINE
DCOM- 20080902
LR  - 20080819
IS  - 0366-6999 (Print)
IS  - 0366-6999 (Linking)
VI  - 121
IP  - 13
DP  - 2008 Jul 5
TI  - Effects of delayed brain-derived neurotrophic factor application on cochlear 
      pathology and auditory physiology in rats.
PG  - 1189-96
AB  - BACKGROUND: The development and maintenance of spiral ganglion cells (SGCs) 
      appear to be supported by neurotrophins. Removal of this support leads to their 
      gradual degeneration. Intracochlear infusion with neurotrophins can provide 
      trophic support to SGCs in animal deafness models if given shortly after 
      deafening. However, it is not known whether delayed intervention will provide 
      similar protection, which might be clinically relevant. The present research was 
      conducted to determine the effects of brain-derived neurotrophic factor (BDNF) 
      administration on the capacity of the peripheral processes to resprout. METHODS: 
      The left cochlea of 20 profoundly deafened rats, which were divided into 2 groups 
      equally, was implanted with an electrode and drug-delivery system 30 days after 
      deafening. Either BDNF or artificial perilymph (AP) was delivered continuously 
      for 28 days. Electrically evoked auditory brainstem responses (EABRs) were 
      recorded during the period. SGC body and peripheral process density were 
      measured. RESULTS: The EABR thresholds of AP increase continually. Those of BDNF 
      increase slowly at the beginning then decrease, and were significantly less than 
      those of the AP group from day 14 to 28 (P < 0.01). In terms of SGC and 
      peripheral process density, the difference between the treated and control ears 
      of BDNF group was clearly significant (P < 0.01), but not in AP group (P > 0.05). 
      Analysis of the left cochlea between the two groups demonstrated that 
      SGC/peripheral process density of the BDNF group was significantly greater than 
      that of the AP group. Finally, a functional formula was developed relating the 
      last EABR threshold and SGC density and process density, which was as follows: T 
      = 466.184 - 2.71 (F.B.L). CONCLUSIONS: Under the conditions of delayed 
      intervention following 30 days after deafening in rats, it can be concluded that 
      BDNF enhances SGC bodies and peripheral processes survival after differentiation 
      and so improves auditory sensitivity. SGC peripheral processes influence the 
      auditory sensitivity.
FAU - Song, Bing-nan
AU  - Song BN
AD  - Department of Otorhinolaryngology, Beijing Tongren Hospital, Capital Medical 
      University, Beijing, China.
FAU - Li, Yong-xin
AU  - Li YX
FAU - Han, De-min
AU  - Han DM
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - China
TA  - Chin Med J (Engl)
JT  - Chinese medical journal
JID - 7513795
RN  - 0 (Brain-Derived Neurotrophic Factor)
SB  - IM
MH  - Animals
MH  - Brain-Derived Neurotrophic Factor/*administration & dosage
MH  - Cell Survival/drug effects
MH  - Evoked Potentials, Auditory, Brain Stem/*drug effects
MH  - Male
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Spiral Ganglion/cytology/*drug effects
EDAT- 2008/08/20 09:00
MHDA- 2008/09/03 09:00
CRDT- 2008/08/20 09:00
PHST- 2008/08/20 09:00 [pubmed]
PHST- 2008/09/03 09:00 [medline]
PHST- 2008/08/20 09:00 [entrez]
PST - ppublish
SO  - Chin Med J (Engl). 2008 Jul 5;121(13):1189-96.