Serotonergic projections from the raphe nuclei to the subthalamic nucleus; a retrograde- and anterograde neuronal tracing study

TY - JOUR

T1 - Serotonergic projections from the raphe nuclei to the subthalamic nucleus; a retrograde- and anterograde neuronal tracing study

AU - Reznitsky, Martin

AU - Plenge, Per

AU - Hay-Schmidt, Anders

PY - 2016/1/26

Y1 - 2016/1/26

N2 - The objective of this study is to establish which subdivision of the dorsal raphe nucleus (DRN) supplies serotonergic projections to the subthalamic nucleus (STN) in the rat brain. Several studies in recent years have shown that serotonin (5-HT) might have a therapeutic role in the most prevalent basal ganglia (BG) movement disorder, Parkinson's disease (PD), but, because of the depletion of dopaminergic input to the BG, l-DOPA has been the main treatment for PD patients. Autoradiography showed that serotonin receptors 5-HT1B and 5-HT2C and the serotonin transporter were present in STN, whereas the 5-HT1A and 5-HT2A not were present. Retrograde tracer FluoroGold or Choleratoxin subunit B were iontophoretically delivered in the STN and combined with immunohistochemistry for 5-HT in order to map the topographic organization in the dorsal raphe system. The study showed that approximately 320+/-137 neurons were retrogradely traced from each STN to the DRN, located mainly in the dorsal- and ventrolateral DRN, and of these 108+/-42 or 34% co-localized 5-HT. Additionally anterograde tracer PHA-L was injected in the DRN to confirm projections to STN and accordingly only a sparse number of axon terminals were observed in the STN.

AB - The objective of this study is to establish which subdivision of the dorsal raphe nucleus (DRN) supplies serotonergic projections to the subthalamic nucleus (STN) in the rat brain. Several studies in recent years have shown that serotonin (5-HT) might have a therapeutic role in the most prevalent basal ganglia (BG) movement disorder, Parkinson's disease (PD), but, because of the depletion of dopaminergic input to the BG, l-DOPA has been the main treatment for PD patients. Autoradiography showed that serotonin receptors 5-HT1B and 5-HT2C and the serotonin transporter were present in STN, whereas the 5-HT1A and 5-HT2A not were present. Retrograde tracer FluoroGold or Choleratoxin subunit B were iontophoretically delivered in the STN and combined with immunohistochemistry for 5-HT in order to map the topographic organization in the dorsal raphe system. The study showed that approximately 320+/-137 neurons were retrogradely traced from each STN to the DRN, located mainly in the dorsal- and ventrolateral DRN, and of these 108+/-42 or 34% co-localized 5-HT. Additionally anterograde tracer PHA-L was injected in the DRN to confirm projections to STN and accordingly only a sparse number of axon terminals were observed in the STN.

KW - 5-HT

KW - Dorsal raphe nucleus

KW - Immunohistochemistry

KW - In situ hybridization

KW - Parkinson's disease

KW - STN

U2 - 10.1016/j.neulet.2015.11.035

DO - 10.1016/j.neulet.2015.11.035

M3 - Journal article

C2 - 26683905

AN - SCOPUS:84951129053

SN - 0304-3940

VL - 612

SP - 172

EP - 177

JO - Neuroscience Letters

JF - Neuroscience Letters

ER -