Presynaptic 5-HT1A is related to 5-HTT receptor density in the human brain

TY - JOUR

T1 - Presynaptic 5-HT1A is related to 5-HTT receptor density in the human brain

AU - Bose, Subrata K

AU - Mehta, Mitul A

AU - Selvaraj, Sudhakar

AU - Howes, Oliver

AU - Hinz, Rainer

AU - Rabiner, Eugenii A

AU - Grasby, Paul M

AU - Turkheimer, Federico E

AU - Murthy, Venkatesha

PY - 2011/10

Y1 - 2011/10

N2 - 5-Hydroxytryptamine (5-HT or serotonin) is an important neurotransmitter for a number of brain functions and widely distributed throughout the brain. Physiological and pharmacological relationship between 5-HT1A receptors and serotonin transporter (5-HTT) in the regulation of 5-HT neurotransmission has now been documented. A relationship between 5-HT1A receptors and 5-HTT is also suggested by the pathophysiology of depression and the mechanism of action of antidepressants. We have scanned 42 healthy adults with both [11C] WAY-100635 and [11C] DASB to investigate the anatomical co-distribution of multiple serotonergic markers. We hypothesized that lower 5-HTT densities in the dorsal raphe nucleus (DRN) and limbic regions will be accompanied by lower 5-HT1A receptor density in the same regions, contributing to the 5-HT1A receptor desensitization. In addition, variations in DRN 5-HT1A receptor density can theoretically influence the density and/or function of other serotonin receptor subtypes and the 5-HTT consequent to changes in serotonergic tone. In a comparatively large sample of volunteers, we have shown that the relationship between 5-HT1A and 5-HTT PET indices was complex. We were unable to demonstrate robust, intra-regional relationships between 5-HT1A and 5-HTT densities. Inter-regionally, DRN 5-HT1A receptors were related to cortical (temporal and frontal regions) and paralimbic (insula), but not limbic 5-HTT. This latter finding may reflect differences in 5-HT tone between individuals, and highlights probable substrates sensitive to variations in DRN 5-HT function.

AB - 5-Hydroxytryptamine (5-HT or serotonin) is an important neurotransmitter for a number of brain functions and widely distributed throughout the brain. Physiological and pharmacological relationship between 5-HT1A receptors and serotonin transporter (5-HTT) in the regulation of 5-HT neurotransmission has now been documented. A relationship between 5-HT1A receptors and 5-HTT is also suggested by the pathophysiology of depression and the mechanism of action of antidepressants. We have scanned 42 healthy adults with both [11C] WAY-100635 and [11C] DASB to investigate the anatomical co-distribution of multiple serotonergic markers. We hypothesized that lower 5-HTT densities in the dorsal raphe nucleus (DRN) and limbic regions will be accompanied by lower 5-HT1A receptor density in the same regions, contributing to the 5-HT1A receptor desensitization. In addition, variations in DRN 5-HT1A receptor density can theoretically influence the density and/or function of other serotonin receptor subtypes and the 5-HTT consequent to changes in serotonergic tone. In a comparatively large sample of volunteers, we have shown that the relationship between 5-HT1A and 5-HTT PET indices was complex. We were unable to demonstrate robust, intra-regional relationships between 5-HT1A and 5-HTT densities. Inter-regionally, DRN 5-HT1A receptors were related to cortical (temporal and frontal regions) and paralimbic (insula), but not limbic 5-HTT. This latter finding may reflect differences in 5-HT tone between individuals, and highlights probable substrates sensitive to variations in DRN 5-HT function.

KW - Piperazines

KW - Positron-Emission Tomography

KW - Humans

KW - Presynaptic Terminals

KW - Adult

KW - Receptor, Serotonin, 5-HT1A

KW - Brain

KW - Serotonin Plasma Membrane Transport Proteins

KW - Middle Aged

KW - Pyridines

KW - Male

U2 - 10.1038/npp.2011.113

DO - 10.1038/npp.2011.113

M3 - Article

C2 - 21750580

SN - 1740-634X

VL - 36

SP - 2258

EP - 2265

JO - Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology

JF - Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology

IS - 11

ER -