Nerve growth factor regulates synaptophysin expression in developing trigeminal ganglion neurons in vitro☆
Received 7 May 2008; accepted 29 September 2008. published online 19 November 2008.
Abstract
The role of neuronal growth factors in synaptic maturation of sensory neurons, including trigeminal ganglion (TG) neurons, remains poorly understood. Here, we show that nerve growth factor (NGF) regulates the intracellular distribution of the synaptic vesicle protein synaptophysin (Syp) in newborn rat TG neurons in vitro. While reducing the number of Syp-positive cell bodies, NGF dramatically increases Syp immunoreactivity in both proximal and distal segments of the neurite. Intriguingly, the increase in Syp immunoreactivity occurs only in neuron-enriched cultures, in which the number of non-neuronal cells is significantly reduced. Together, our data indicate that NGF is a candidate molecule involved in early postnatal maturation of TG neurons, including control of presynaptic assembly, and thereby formation of synaptic connections.
aDepartment of Integrative Biosciences, Oregon Health and Science University, 611 SW Campus Drive, Portland, OR 97239, USA
bDepartment of Endodontics, Oregon Health and Science University, Portland, OR, USA
cDepartment of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR, USA
Corresponding author. Address: Department of Integrative Biosciences, Oregon Health and Science University School of Dentistry, 611 SW Campus Drive, Portland, OR 97239, USA. Tel.: +1 503 418 0190; fax: +1 503 494 8554.
☆ This work was funded by the Medical Research Foundation of Oregon and National Institutes of Health (HL076113) grants to A.B.
ABSTRACT