Quantitative and morphometric data indicate precise cellular interactions between serotonin terminals and postsynaptic targets in rat substantia nigra

Serotonin and Dopamine Transporter Availabilities Correlate with the Loudness Dependence of Auditory Evoked Potentials in Patients with Obsessive-Compulsive Disorder

“…This result again favors the serotonergic aspects of LD modulation. Nevertheless, the correlation of LD with dopaminergic measures, such as the striatal b-CIT binding (DAT availability), is consistent with the notion of central interconnections of the serotonergic and dopaminergic systems (Hervé et al, 1987;Parsons and Justice, 1993;Moukhles et al, 1997). Functional interactions between SERT and DAT have also been reported by Kugaya et al (2003) using b-CIT and SPECT in healthy subjects and patients with depression; the administration of antidepressant drugs (selective serotonin reuptake inhibitors (SSRIs)) in healthy controls and depressed patients led to a decrease in SERT and to an unexpected increase in DAT availability, suggesting an SSRI-induced modulation of the dopaminergic system.…”

“…However, given functional interactions between monoaminergic systems (Moukhles et al, 1997;Kugaya et al, 2003), this would not be contradictory to the notion of LD as a clinical serotonergic marker (Hegerl et al, 2001;Croft et al, 2001). New models for b-CIT measurements with an improved separation of b-CIT binding to SERT and DAT as proposed by Ryding et al (2004), as well as the use of highly selective radioligands for SERT, such as ADAM for SPECT or DASB for PET (Oya et al, 2000;Kauppinen et al, 2003;Wilson et al, 2002;Frankle et al, 2004), might help to advance in vivo studies and to investigate the different aspects of central monoaminergic function more accurately.…”

Serotonin modulation of the basal ganglia circuitry: therapeutic implication for Parkinson's disease and other motor disorders

“…1), sending projections to the corpus striatum, the globus pallidus (GP), the subthalamic nucleus (STN), the substantia nigra (SN) and the pedunculopontino nucleus (PPN), and provides most of the innervation of the prefrontal cortex, including the motor cortices. 5-HT-containing cell bodies of the raphe send projections to both dopaminergic (DAergic) and gamma-aminobutyric acidergic (GABAergic) cells in the SN and to their terminal 424 fields (Herve´et al, 1987;Van Bockstaele et al, 1993;Moukhles et al, 1997). Moreover, electron microscopy demonstrates the presence of synaptic contacts of [ 3 H]5-HT-labelled terminals with both DAergic and non-DAergic dendrites in the SN pars compacta (SNc) and reticulata (SNr) (Herve´et al, 1987;Moukhles et al, 1997;Lee et al, 2000).…”

“…5-HT-containing cell bodies of the raphe send projections to both dopaminergic (DAergic) and gamma-aminobutyric acidergic (GABAergic) cells in the SN and to their terminal 424 fields (Herve´et al, 1987;Van Bockstaele et al, 1993;Moukhles et al, 1997). Moreover, electron microscopy demonstrates the presence of synaptic contacts of [ 3 H]5-HT-labelled terminals with both DAergic and non-DAergic dendrites in the SN pars compacta (SNc) and reticulata (SNr) (Herve´et al, 1987;Moukhles et al, 1997;Lee et al, 2000). The DRN innervates, together with the MRN, the ventral part of the hippocampus, the nucleus accumbens and various nuclei of the thalamus, among them the ventral lateral nuclear group that processes motor information and the hippocampus (Azmitia and Segal, 1978;Jacobs and Azmitia, Fig.…”

“…It has been calculated that the density of 5-HT-immunoreactive varicosities in the SNr is in the order of 9 Â 10 6 /mm 3 , of which about 74% form synaptic specializations with GABAergic projection neurons (Moukhles et al, 1997). This picture gives an idea of the great influence that 5-HT could have on the activity of SNr neurons.…”