Differential electrophysiological changes in striatal output neurons in XXXX .

@entity2227 @entity37746 @entity146 @entity935 @entity19 @entity2348 @entity2033 @entity2845 @entity1773 @entity9767
There is considerable evidence that alterations in striatal medium-sized spiny neurons (MSSNs) giving rise to the direct ( @entity37746 -expressing) and indirect ( @entity9767 -expressing) pathways differentially contribute to the phenotype of @entity2033 ( @entity2033 ). To determine how each subpopulation of MSSN is functionally affected, we examined spontaneous excitatory postsynaptic currents (sEPSCs) and @entity935 (DA) modulation in two @entity2033 @entity19 models, the YAC128 and the BACHD (a @entity2348 ). These @entity19 also expressed enhanced green fluorescent protein (EGFP) under the control of the promoter for either DA D1 or D2 receptors to identify neurons. In early symptomatic YAC128 and BACHD @entity19 , @entity2227 transmission was increased in both D1 and D2 MSSNs, but in different ways. D1 cells displayed increased sEPSC frequencies and decreased paired-pulse ratios (PPRs) while D2 cells displayed larger evoked @entity2227 currents but no change in sEPSC frequencies or PPRs. @entity37746 modulation of sEPSCs was absent in D1-YAC128 cells at the early symptomatic stage but was restored by treating the slices with @entity1773 . In contrast, in fully symptomatic YAC128 @entity19 , @entity2227 transmission was decreased specifically in D1 cells, and @entity37746 modulation was normal in D1-YAC128 cells. Behaviorally, early symptomatic @entity19 showed increased stereotypies that were decreased by @entity1773 treatment. Together, these studies support differential imbalances in @entity2227 and DA transmission in direct and indirect pathway MSSNs. @entity146 at an early stage could be explained by increased @entity2227 activity and DA tone in direct pathway neurons, whereas @entity2845 at later stages could result from reduced input onto these neurons.
