Serotonergic modulation of dopamine measured with [11C]raclopride and PET in normal human subjects

Abstract

Objective: This study was undertaken to measure serotonergic modulation of dopamine in vivo by using positron emission tomography (PET)

Interaction between serotonin transporter and dopamine D2/D3 receptor radioligand measures is associated with harm avoidant symptoms in anorexia and bulimia nervosa

“…Rather, 5-HTT binding was associated with HA, but only in relationship to 5-HTT and DA interactions, raising the possibility that 5-HTT may have a modulatory role on DA activity, with the latter being associated with HA. In support of this idea, agents that are relatively 5-HT specific, such as psilocybin (Vollenweider et al 1999), fenfluramine (Smith et al 1997), and citalopram (Tiihonen et al 1996) alter [ 11 C]raclopride binding. It is important to note that 5-HT and DA neural systems are complex.…”

Selective serotonin reuptake inhibitor (SSRI) modulation of striatal dopamine measured with [11C]‐raclopride and positron emission tomography

“…Specifically, radiotracer binding to the dopamine (D2) receptor has been shown repeatedly to be altered by administration of agents that increased or decreased endogenous dopamine concentrations by direct or indirect pharmacologic mechanisms, using positron emission tomography (PET) or single photon emission computed tomography methods [single photon emission computed tomography (SPECT)] (e.g., Dewey et al, 1991, 1993a,b; Innis et al, 1992; Smith et al, 1997; Volkow et al, 1994). Acute administration of agents that directly (d-amphetamine, methylphenidate or cocaine) or indirectly increase dopamine concentrations through interactions with other neurotransmitter systems (e.g., fenfluramine, scopolamine, ketamine for the serotonergic, cholinergic, and glutamatergic systems, respectively) resulted in a decrease in radio-tracer binding, presumably due to increased competition between dopamine and the radiotracer for binding to the D2 receptor (Breier et al, 1998; Dewey et al, 1990, 1995; Smith et al, 1997, 1998). Conversely, agents that decreased dopamine concentrations directly (reserpine, α-methyl p -tyrosine) or indirectly (lorazepam, γ-vinyl GABA) resulted in an increase in receptor binding due to reduced competition between dopamine and the radiotracer for binding to the D2 receptor (e.g., Dewey et al, 1992; Laruelle et al, 1997).…”

Molecular imaging of neuropsychiatric symptoms in Alzheimer's and Parkinson's disease

“…Neurochemical imaging studies have elucidated serotonergic and dopaminergic mechanisms of NPS in AD and PD. Further, interactions between neurotransmitter systems that can be imaged with PET may be more informative mechanistically and with respect to treatment development (Smith et al, 1997). Thus, this may explain why therapeutic strategies for late-life depression may be less effective in depression in AD and PD and other mechanisms may be more effective, such as receptor modulators (e.g.…”