Objective To observe the association of vesicular glutamate transporter of typeⅠ (VGluT1 ) like immunoreactive(LI) ,the differentiation-associated Na+ dependent inorganic phosphate cotransporter(DNPI) LI and glutami cacid decarboxy lase(GAD) LI terminals with GABAA receptor ?3 subunit(GABAAR ?3) LI neurons in mesencephalic trige minal nucleus of the rat.Methods Triple immun of luorescencehis to chemical staining technique and confo call aser scanning micros copy were used.Results Alargenumber of neuronal cell bodies showed GABAA R?3 LI immunoreactivity atallrostrocaudal level softhe Vme ,and most of GABAAR ?3 LI cells were large (2 5 5 0 ?m)pseudouni polarneurons.The dense VGluT1 LI,DNPL LI and GAD LIterminal sdistri buted widelyin Vme ,some VGlu T1 DNPI LI and GAD LIterminals surrounded the somata of the GABAAR ?3 LI Vmeneurons ,and made close contacts with them .Conclusion Proprioceptive sensory signals from the or of acialregionmight be modulated at the level of the primary afferent cell bodies in the Vme both by glutamatergic and GABAergic axonal terminals from other brain areas,and the effect of GABAergic terminals might be mediated by post synaptical GABAA receptors .