[Abstract Title]. - Society for Neuroscience

stimuli, but is potentiated by sustained synaptic activity. This mechanism may therefore be a
form of glial “memory” of neuronal activity.
Disclosures: T.M. Pirttimaki , None; R. Parri, None.
Poster
242. Glial Neuronal Interactions: Glutamate and Calcium
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 242.19/J2
Topic: B.11.a. Synapses
Support: BBSRC
Title: NG2-glia have the mechanisms for communication with neurons and astrocytes at a
tetrapartite synapse
Authors: *R. J. WIGLEY, A. M. BUTT;
Pharm. & Biomed. Sci., Cell. Neurophysiol., Portsmouth, United Kingdom
Abstract: NG2-glia are identified by the expression of the chondroitin sulphate proteoglycan
NG2 on their cell surface. NG2-glia form contacts with neurons at synapses and respond to
neuronally produced glutamate (Bergles et al. 2000). We have studied these NG2-glial cells,
together with astrocytes, to investigate their involvement at the tripartite synapse that may exist
between pre- and post- synaptic neurons in the presence of a synaptic astrocyte. Experiments
were carried out using a transgenic mouse line whose astrocytes express green fluorescent
protein under the glial fibrillary acidic protein (GFAP) promoter. Mice aged post-natal day (P)
15 and above were humanely killed according to the UK Home Office Animals (Scientific
Procedures) Act 1986. Brains were removed and fixed in 4% paraformaldehyde before being
sliced to sagital sections of 100µm on a vibrotome and stained for the presence of NG2-glia
(NG2), synapses (synaptophysin), glutamate transport vesicles (vGLUT1) and ionotrophic
AMPA glutamate receptors (GluR4). Images were captured on a Zeiss Meta 510 confocal
microscope and analysed by deconvolution and colocalization studies using Volocity
(Improvision, UK). The three-dimensional images show that NG2-glia are in direct proximity to
neuronal synapses and form points of contact with astrocytes that express both vGLUT1 and
GluR4. The results suggest that NG2-glia are a component of a four way communication system
at a tetrapartite synapse and may have an important functional role in glutamate transmission.
Thus NG2-glia are integrated into the neural-glial functional unit of the CNS.
Disclosures: R.J. Wigley, None; A.M. Butt, None.