Influence of the combination of two neurotrophic factors on the survival of nerve growth factor receptor positive neurons in vitro

Shuilong LENG; Dahong LONG

ABSTRACT

BACKGROUND:

Lot of researches has been made on investigating the influence of neurturin(NTN) on dopaminergic neurons,motor neurons,sensory neurons and sympathetic neurons in respect of its enhancing survival and neuroprotective potential. But reports about its influence on cholinergic neurons still remained less.

OBJECTIVE:

To study the influence of NTN combined with nerve growth factor(NGF) on the survival of NGF receptor positive neurons in vitro.

DESIGN:

A repeated measurement and experimental study. based on cell model.

SETTING:

Department of anatomy in a university.MATERIALS This study was carried out at the Human Anatomical Department of Guangzhou Medical College between September 2001 and June2002. Neonatal SD rats were adopted,DMEM/F12 culture medium supplemented with 20 g/L additive without serum were filtered and sterilized for cell culture.

METHODS:

Rats were divided into four groups NGF group,NTN group,NGF + NTN group and control group. Cells of the former three groups were cultured with NGF,NTN and NGF + NTN of 100 μg/L respectively,which were replaced by culture medium in control group. Cholinergic neurons derived from neonatal rat basal forebrain were primary cultured for observing the influence of NTN,NGF on their survival by using immunohistochemical combined imaging analysis method.MAIN OUTCOME

MEASURES:

The survival rate and growing state of NGFR positive neurons derived from forebrain of neonatal rats when cultured for 4 days and 8 days in vitro.

RESULTS:

In 4-day culture,indexes of NTN group were significantly different from control group( P ＜ 0. 05 ),and indexes of NGF + NTN group were better than those of NGF group or NTN group( P ＜ 0. 05); in 8-day culture,all indexes except the number of neuronal processes in NTN group were similar to control group( P ＞ 0.05),and indexes of NGF + NTN group were still better than that of NGF group or NTN group( P ＜ 0. 05); but the number of NGF-R positive neuronal processes in NTN group was more that that in NGF group ( P ＜ 0. 05).

CONCLUSION:

NTN has neurotrophic effect on NGF-R positive neurons of neonatal rat basal forebrain in vitro by relatively shorter acting time,and the number of neuronal processes induced by NTN is stronger than NGF; Moreover NTN combined with NGF exerts better effect than NTN or NGF alone in vitro.