S-Ketamine Reverses Hippocampal Dendritic Spine Deficits in Flinders Sensitive Line Rats Within 1 h of Administration

TY - JOUR

T1 - S-Ketamine Reverses Hippocampal Dendritic Spine Deficits in Flinders Sensitive Line Rats Within 1 h of Administration

AU - Treccani, Giulia

AU - Ardalan, Maryam

AU - Chen, Fenghua

AU - Musazzi, Laura

AU - Popoli, Maurizio

AU - Wegener, Gregers

AU - Nyengaard, Jens Randel

AU - Müller, Heidi Kaastrup

PY - 2019/11

Y1 - 2019/11

N2 - When administered as a single subanesthetic dose, the N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine, produces rapid (within hours) and relatively sustained antidepressant actions even in treatment-resistant patients. Preclinical studies have shown that ketamine increases dendritic spine density and synaptic proteins in brain areas critical for the actions of antidepressants, yet the temporal relationship between structural changes and the onset of antidepressant action remains poorly understood. In this study, we examined the effects of a single dose of S-ketamine (15 mg/kg) on dendritic length, dendritic arborization, spine density, and spine morphology in the Flinders Sensitive and Flinders Resistant Line (FSL/FRL) rat model of depression. We found that already 1 h after injection with ketamine, apical dendritic spine deficits in CA1 pyramidal neurons of FSL rats were completely restored. Notably, the observed increase in spine density was attributable to regulation of both mushroom and long-thin spines. In contrast, ketamine had no effect on dendritic spine density in FRL rats. On the molecular level, ketamine normalized elevated levels of phospho-cofilin and the NMDA receptor subunits GluN2A and GluN2B and reversed homer3 deficiency in hippocampal synaptosomes of FSL rats. Taken together, our data suggest that rapid formation of new spines may provide an important structural substrate during the initial phase of ketamine's antidepressant action.

AB - When administered as a single subanesthetic dose, the N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine, produces rapid (within hours) and relatively sustained antidepressant actions even in treatment-resistant patients. Preclinical studies have shown that ketamine increases dendritic spine density and synaptic proteins in brain areas critical for the actions of antidepressants, yet the temporal relationship between structural changes and the onset of antidepressant action remains poorly understood. In this study, we examined the effects of a single dose of S-ketamine (15 mg/kg) on dendritic length, dendritic arborization, spine density, and spine morphology in the Flinders Sensitive and Flinders Resistant Line (FSL/FRL) rat model of depression. We found that already 1 h after injection with ketamine, apical dendritic spine deficits in CA1 pyramidal neurons of FSL rats were completely restored. Notably, the observed increase in spine density was attributable to regulation of both mushroom and long-thin spines. In contrast, ketamine had no effect on dendritic spine density in FRL rats. On the molecular level, ketamine normalized elevated levels of phospho-cofilin and the NMDA receptor subunits GluN2A and GluN2B and reversed homer3 deficiency in hippocampal synaptosomes of FSL rats. Taken together, our data suggest that rapid formation of new spines may provide an important structural substrate during the initial phase of ketamine's antidepressant action.

KW - Antidepressants

KW - Cofilin

KW - Dendritic Spines

KW - Homer3

KW - Ketamine

KW - Synaptosomes

U2 - 10.1007/s12035-019-1613-3

DO - 10.1007/s12035-019-1613-3

M3 - Journal article

C2 - 31037646

SN - 0893-7648

VL - 56

SP - 7368

EP - 7379

JO - Molecular Neurobiology

JF - Molecular Neurobiology

IS - 11

ER -