Ontogenetic maturation of striatal synapses

AZCURRA J.M., RODRIGUEZ C., FOSSATI M., SOIZA REILLY M., BERL T., RIVARD C. AND CAPASSO J.M.

Cancún

Congreso; Join Meeting of the International Society for Neurochemistry and the American Society for Neurochemistry; 2007

ISN, ASN

Accurate neurochemical description of striatum developmentalstages are of surmount importance for pharmacologicaltreatment of neuropsychiatric conditions like hyperactivityand drug addiction. An example of the complexity of postnatalprocesses in these ganglia are the presence of two differentperiods for the adjustment of adult receptors expression byphysiological activity. In the case of cholinergic and dopaminergicsynapses, motor activity (circular running for 1000m inseven sessions) induce a life lasting decreased expression ofabout 45% of receptors proteins in synaptic membranes, aswell as the corresponding mRNA levels, if applied during anarrow temporal window (PN days 30?37). On the other hand,for glutamaergic excitatory asymmetric synapses a similareffect in receptor level is produced after identical trainingconditions, but in totally different temporal window (PN days20?27).Measurement of the mRNA levels of receptors such asNMDA, mAchR M1 and M4 by semiquantitative andquantitative (real time) PCR show that their decrease topermanent adult levels, does not occur soon after training,regardless of the critical period utilizes, but is delayed untill PNdays 67?72. We speculate that this later age is an indicator ofthe final stage of postnatal development in the rat. To obtain amore direct probe of this hypotesis DNA microarray studies(Affimetrix GeneChips Rat Genome 230 2.0 Array) wereperformed using mRNA obtained at PN days 71?79 from thestriata of rats that ran or did not run during the critical periodPN days 30?37. Results support that maturational events in ratstriatum are ending at PN78 at least at the transcriptional level.