P2Y1 receptor switches to neurons from glia in juvenile versus neonatal rat cerebellar cortex.
BACKGROUND
In the CNS, several P2 receptors for extracellular nucleotides are identified on neurons and glial cells to participate to neuron-neuron, glia-glia and glia-neuron communication.


RESULTS
In this work, we describe the cellular and subcellular presence of metabotropic P2Y1 receptor in rat cerebellum at two distinct developmental ages, by means of immunofluorescence-confocal and electron microscopy as well as western blotting and direct membrane separation techniques. At postnatal day 21, we find that P2Y1 receptor in addition to Purkinje neurons, is abundant on neuronal specializations identified as noradrenergic by anatomical, morphological and biochemical features. P2Y1 receptor immunoreactivity colocalizes with dopamine beta-hydroxylase, tyrosine hydroxylase, neurofilament light chain, synaptophysin and flotillin, but not with glial fibrillary acidic protein for astrocytes. P2Y1 receptor is found enriched in membrane microdomains such as lipid rafts, in cerebellar synaptic vesicles, and is moreover visualized on synaptic varicosities by electron microscopy analysis. When examined at postnatal day 7, P2Y1 receptor immunoreactivity is instead predominantly expressed only on Bergmann and astroglial cells, as shown by colocalization with glial fibrillary acidic protein rather then neuronal markers. At this age, we moreover identify that P2Y1 receptor-positive Bergmann fibers wrap up doublecortin-positive granule cells stretching along them, while migrating through the cerebellar layers.


CONCLUSIONS
Membrane components including purinergic receptors are already known to mediate cellular contact and aggregation in platelets. Our results suggesting a potential role for P2Y1 protein in cell junction/communication and development, are totally innovative for the CNS.
Amadio
Susanna
S
Santa Lucia Foundation, Roma, Italy. s.amadio@hsantalucia.it <s.amadio@hsantalucia.it>
Vacca
Fabrizio
F
Martorana
Alessandro
A
Sancesario
Giuseppe
G
Volonté
Cinzia
C
D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D002465:Cell Movement; D002531:Cerebellum / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D000089662:Doublecortin Protein; D021962:Membrane Microdomains / Q000737:chemistry; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D010641:Phenotype; D051381:Rats; D017208:Rats, Wistar; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000378:metabolism*; D058472:Receptors, Purinergic P2Y1; D013569:Synapses / Q000378:metabolism / Q000648:ultrastructure; D013574:Synaptosomes / Q000737:chemistry; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
C000714848:Dcx protein, rat; D000089662:Doublecortin Protein; C546384:P2ry1 protein, rat; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D014446:Tyrosine 3-Monooxygenase; D004299:Dopamine beta-Hydroxylase