Cortical spiking activity entrainment with beta oscillations is enhanced after nigrostriatal degeneration and when L-DOPA effects have worn off

DANIELA PIÑA-NOVO; GUSTAVO MURER; MARIANO BELLUSCIO

Congreso; XXXIV Congreso Anual Sociedad Argentina de Investigación en Neurociencias 2019; 2019

Abnormalinvoluntary movements known as L-DOPA-induced dyskinesia (LID) are acommon complication in Parkinson's disease (PD) after prolongedtreatment with L-DOPA, which is the gold standard medication. Littleis known about the oscillatory activity associated with LID,especially in the motor cortex (MC). However recent studies show thatexaggerated beta activity (15?35 Hz) who emerge in the basalganglia after nigrostriatal degeneration, correlate with motorimpairment in PD and can be suppressed by LID. Our previouscharacterization in MC disclosed a similar pattern, with an increasednumber, duration and power of beta events. Interestingly this patternwas reverted during the acute effect of L-DOPA, but reappeared whenL-DOPA effects have worn off. Here we sought to identify corticalneuronal populations related to this rhythm. We performed recordingsof single unit activity by means of high density electrodes inprimary MC of parkinsonian mice before and after L-DOPA regime thatinduced LID. We found an increased mean firing rate in bothconditions. Also, phase preference of spiking activity to betaoscillations was higher in lesioned than in sham animals. Thispattern was present both in putative pyramidal neurons andinterneurons. These results reveal a better entrainment of neuronalactivity with beta oscillations in the parkinsonian condition, whichis not reversed by chronic L-DOPA administration, and could explainthe increased beta power previously observed. p { margin-bottom: 2.12mm; direction: ltr; color: rgb(0, 0, 0); background: transparent none repeat scroll 0% 0%; }p.western { font-family: "Times New Roman", serif; font-size: 12pt; }p.cjk { font-family: "SimSun", "宋体"; font-size: 12pt; }p.ctl { font-family: "Lucida Sans", sans-serif; font-size: 12pt; }