Immunocytochemical localization of metabotropic glutamate receptor type I alpha and tubulin in rat brain

The distribution of mGlu(1 alpha) receptor and tubulin was immunocytochemic ally examined in the rat cerebellar cortex and primary rat cortical neurons at both immunofluorescence and electron microscopic level. In cryosections from rat cerebellar cortex mGlu(1 alpha) receptor immunoreactivity was exp ressed in cell bodies and dendrites of Purkinje and basket cells of the cer ebellar molecular layer. Tubulin immunoreactivity was concentrated in the d endritic tree of the cerebellar molecular layer, as well as in the granule cell layer. In primary rat cortical neurons, both proteins colocalized thro ughout the proximal and distal dendrites of these cells. At the electron mi croscopic revel, the receptor was present in dendritic shafts and dendritic spines of Purkinje cells at perisynaptic sites of asymmetrical synapses. I mmunoreactivity corresponding to tubulin was associated with the plasma mem brane of dendritic shafts of Purkinje cells, as well as throughout its cyto plasm as part of the cytoskeletal components. Interestingly, double labelin g for both proteins reveals an association of tubulin with mGlu(1 alpha) re ceptor at the plasma membrane level of dendritic shafts of Purkinje cells. This suggests that tubulin interacts with mGlu(1 alpha) receptor and may be involved in the anchoring of the receptor to the plasma membrane. NeuroRep ort 12:1285-1291 (C) 2001 Lippincott Williams & Wilkins.