Skip to main content
Fig. 6 | Acta Neuropathologica Communications

Fig. 6

From: Regulation of dopamine neurotransmission from serotonergic neurons by ectopic expression of the dopamine D2 autoreceptor blocks levodopa-induced dyskinesia

Fig. 6

Ectopic DRN D2Rs expression reduces 5HT neuronal firing. a Top: Traces show typical single-unit recordings of isolated DRN 5-HT neurons (5-HT+) (left) and non-serotonergic (5-HT-) neurons (right). Middle/Bottom: 5-HT neurons often exhibit burst firing with short inter-spike intervals as well as regular spiking. b Systemic administration of the selective 5-HT1A agonist 8-OH-DPAT (1 μg/kg, i.v.), but not saline (0.9%) vehicle, suppressed the spontaneous firing of a DRN neuron exhibiting spike characteristic of a 5-HT cell. A return to baseline firing was observed after the local application of WAY-100635 ((100 μg/kg, i.v.), vertical blue bars). c-d firing rate distributions of DRN neurons recorded in BFP and D2Rs expressing rats before and after the application of saline, 8-OH-DPAT and WAY-100635. Putative 5-HT neurons in both groups exhibited similar inhibitory responses to 5-HT1AR agonist and reversal of inhibition by 5-HT1AR antagonism. e Firing rate histograms showing the effects of the D2R agonist quinpirole (500 μg/kg, i.v.) on 5-HT neurons recorded in BFP (top) or AAV-D2Rs (bottom) injected rats. Control neurons that responded to Quin increased their firing activity to varying degrees, whereas the majority of 5-HT cells recorded in AAV-D2Rs injected rats were inhibited. f Cumulative electrophysiological data showing the mean ± S.E.M. firing rates of 5-HT DRN cells transfected with BFP or D2Rs prior to, and after Quin administration

Back to article page
\