DYT1 dystonia is a movement disorder caused by a deletion
in the C-term
inal
of the prote
in tors
inA. It is unclear how tors
inA mutation might disrupt cellular processes encod
ing motor activity, and whether this impairment occurs
in specific bra
in regions. Here, we report a selective impairment
of corticostriatal synaptic plasticity
in knock-
in mice heterozygous for 螖-tors
inA (Tor1a
+/螖gag mice) as compared to controls (Tor1a
+/+ mice). In striatal sp
iny neurons from Tor1a
+/螖gag mice, high-frequency stimulation failed to
induce long-term depression (LTD), whereas long-term potentiation (LTP) exhibited
increased amplitude. Of
interest, blockade
of D2 dopam
ine receptors (D2Rs)
increased LTP
in Tor1a
+/+ mice to a level comparable to that measured
in Tor1a
+/螖gag mice and normalized the levels
of potentiation across
mouse groups. A low-frequency stimulation (LFS) protocol was unable to depotentiate corticostriatal synapses
in Tor1a
+/螖gag mice. Muscar
inic M1 acetylchol
ine receptor (mAChR) blockade rescued plasticity deficits. Additionally, we found an abnormal responsiveness
of chol
inergic
interneurons to D2R activation, consist
ing
in an excitatory response rather than the expected
inhibition, further confirm
ing an imbalance between dopam
inergic and chol
inergic signal
ing
in the striatum. Conversely, synaptic activity and plasticity
in the CA1 hippocampal region were unaltered
in Tor1a
+/螖gag mice. Importantly, the M1 mAChR-dependent enhancement
of hippocampal LTP was unaffected
in both genotypes. Similarly, both basic properties
of dopam
inergic nigral neurons and their responses to D2R activation were normal.
These results provide evidence for a regional specificity of the electrophysiological abnormalities observed and demonstrate the reproducibility of such alterations in distinct models of DYT1 dystonia.