Plasticity of Hippocampal Subfield Volume Cornu Ammonis 2+3 Over the Course of Withdrawal in Patients With Alcohol Dependence

Abstract

on plasticity has shown adult neurogenesis in hippocampal subfields. Chronic alcoholism is associated with decreased plasticity and reduced whole hippocampal volume that could contribute to neuropsychiatric characteristics and outcome of the disease.OBJECTIVE To investigate the effect of alcohol abstinence on neuronal plasticity measured as longitudinal volume change in distinct hippocampal subfields. DESIGN, SETTING, AND PARTICIPANTSWe acquired high-resolution structural images of 42 patients addicted to alcohol and 32 healthy control participants. Patients and control participants were both scanned twice, once after withdrawal and 2 weeks later. MAIN OUTCOMES AND MEASURESVolumes of hippocampal subfields cornu ammonis (CA) 2+3, CA4+dentate gyrus, and subiculum were determined with a user-independent segmentation method. RESULTSWe found plasticity effects in bilateral CA2+3 in patients addicted to alcohol. Compared with healthy control participants, patients had lower CA2+3 volume at pretest (t 31 = −0.73, P = .47) and showed a significant normalization of gray matter volume 2 weeks later. Pretest CA2+3 (t 31 = −3.93, P < .001) volume was negatively associated with years of regular alcohol consumption (r 42 = −0.32, P < .05) and more severe alcohol-withdrawal symptoms (r 38 = −0.35, P < .05). Patients with stronger withdrawal symptoms displayed the largest volume increase of CA2+3 (r 38 = 0.55, P < .001). CONCLUSIONS AND RELEVANCEThe observed normalization of the bilateral hippocampal CA2+3 volume deficit matches animal data, showing a strong increase of hippocampal neurogenesis after cessation of alcohol consumption, and fits the reported increase of patients' cognitive function within a few months of alcohol abstinence. The role of CA3 in pattern separation and completion is also critical for formation of hallucinations, which constitute a severe symptom of the withdrawal syndrome. The study adds further biological arguments from structural brain research to abstain from alcohol.

Effect of anxiety on behavioural pattern separation in humans

“…Pattern separation has been recently implicated in various forms of anxiety-related psychopathology (Das, Ivleva, Wagner, Stark, & Tamminga, 2014; Fujii, Saito, Yanaka, Kosaka, & Okazawa, 2014; Kühn et al, 2014), but little is currently known about the effect of anxiety on pattern separation in humans. The present study investigated the effect of an induced anxiety state, evoked by the threat of unpredictable shock, on BPS during the encoding and retrieval stages of an episodic memory task.…”

Structural imaging of hippocampal subfields in healthy aging and Alzheimer’s disease

“…Using this technique, 10 region labels (including subfields per se, but also hippocampal fissure, choroid plexus, fimbria and inferior lateral ventricle) are propagated from an ultra-high resolution template by applying heuristic rules based on the anatomy of the whole hippocampus rather than using internal landmarks within the hippocampus (which are not visible on standard scans). Because this method is user-friendly and directly applicable to standard 1.5T or 3T T1-weighted scans, it has been used extensively over the last several years to study hippocampal changes related to development, aging and various conditions (Aas et al, 2014;Durazzo et al, 2013;Engvig et al, 2012;Ezzati et al, 2014;Francis et al, 2013;Hanseeuw et al, 2011;Haukvik et al, 2014;Hsu et al, 2014;Khan et al, 2014;Krogsrud et al, 2014;Kühn et al, 2014;Lim et al, 2012aLim et al, , 2012bPereira et al, 2014Pereira et al, , 2013Tamnes et al, 2014;Teicher et al, 2012 among others).…”

Therapeutic interventions for alcohol dependence in non-inpatient settings: a systematic review and network meta-analysis (protocol)

“…First, abstinence is the most appropriate and commonly reported outcome for severely dependent drinkers. Second, completely abstaining from alcohol has been shown to improve cognitive function [26, 27] and quality of life [28–30]. …”