Blue cone electroretinogram amplitudes are related to dopamine function in cocaine-dependent patients.

The objective of the study was to examine the relationship between an index of central dopamine function and electroretinographic (ERG) blue cone amplitudes in cocaine-dependent patients. Thus, 17 recently abstinent cocaine-dependent patients had an ERG performed. They also had a lumbar puncture for determination of cerebrospinal (CSF) concentrations of the dopamine metabolite homovanillic acid (HVA). It was found that patients who had reduced ERG blue cone b-wave amplitudes (<0.5 microV) had significantly lower concentrations of CSF HVA than patients who had ERG blue cone b-wave amplitudes greater than 0.5 microV. There was also a significant positive correlation between ERG blue cone amplitudes and CSF HVA concentrations. These results suggest the possibility that ERG blue cone amplitudes may be a neurobiologic marker related to central dopamine function in cocaine-dependent patients.

Self-rated childhood emotional neglect and CSF monoamine indices in abstinent cocaine-abusing adults: possible implications for suicidal behavior.

Non-human primate studies suggest that early environmental influences may have an enduring effect on central serotonin function. Therefore, it was decided to examine in humans whether childhood trauma might be related to cerebrospinal fluid (CSF) concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) as an adult. A total of 29 withdrawn cocaine-dependent patients completed the Childhood Trauma Questionnaire. They also had a lumbar puncture for determination of CSF concentrations of 5-HIAA. CSF concentrations of the dopamine metabolite homovanillic acid (HVA) were also determined. Childhood emotional neglect scores showed significant negative correlations with CSF levels of 5-HIAA and HVA, and patients with emotional neglect scores above the median had significantly lower CSF 5-HIAA and HVA levels than patients with emotional neglect scores at or below the median. These findings suggest the possibility that childhood trauma may have an effect on central monoamine function as an adult.

Cerebrospinal fluid monoamine metabolites in cocaine patients: no relationship to cue-induced craving.

We aimed to examine the relationship between central monoamine metabolites and craving cocaine in cocaine-dependent patients. Cerebrospinal fluid (CSF) monoamine metabolite concentrations were determined in 20 withdrawn cocaine-dependent patients. Patients also participated in a cue-elicited cocaine craving procedure. There were no significant relationships between cocaine craving scores and CSF concentrations of the dopamine metabolite, homovanillic acid, the serotonin metabolite, 5-hydroxyindoleacetic acid, or the norepinephrine metabolite, 3-methoxy-4-hydroxyphenylethylglycol. CSF monoamine metabolite concentrations were not related to cocaine craving in withdrawn cocaine-dependent patients.

Higher levels of CSF homovanillic acid in recently abstinent cocaine-dependent patients.

OBJECTIVE: The authors examined an index of dopaminergic neurotransmission in recently abstinent cocaine-dependent patients. METHOD: CSF concentrations of the dopamine metabolite homovanillic acid (HVA) were determined in 30 recently abstinent cocaine-dependent patients and 69 healthy comparison subjects. RESULTS: The cocaine-dependent patients had a significantly higher mean concentration of CSF HVA than did the healthy comparison group. CONCLUSIONS: Recently abstinent cocaine-dependent patients may show dysregulation of the central dopaminergic system.

Gender effects on persistent cerebral metabolite changes in the frontal lobes of abstinent cocaine users.

OBJECTIVE: Previous studies found functional changes in the frontal brain region and regions with projections to the frontal lobe in cocaine users. The aim of this study was to investigate persistent neurochemical changes in the frontal lobes of subjects with a history of crack cocaine dependence and to determine whether these changes are different in male and female users. METHOD: The frontal gray and white matter of 64 young asymptomatic and abstinent (> 5 months) cocaine users (34 male and 30 female) and 58 healthy comparison subjects without a history of drug abuse was evaluated with localized proton magnetic resonance spectroscopy (1H-MRS). RESULTS: Two-way analysis of variance showed significant cocaine effects on the concentration of frontal gray matter N-acetyl compounds, on the ratio of frontal white matter N-acetyl compounds to creatine levels, on frontal gray and white matter myoinositol levels, and on the ratio of myoinositol to creatine. Significant gender effects were observed for frontal gray matter choline-containing compounds, the ratio of choline-containing compounds to creatine, and the percentage of CSF in both gray and white matter. Interaction effects of cocaine and gender were observed for creatine, N-acetyl/creatine ratio, and myoinositol/creatine ratio in frontal white matter. CONCLUSIONS: Cocaine use is associated with neuronal injury (with decreased N-acetyl compounds) in the frontal cortex and glial activation (with increased myoinositol) in both frontal gray and white matter. In the frontal lobe, cocaine affects male users differently than female users. Future studies on the effects of cocaine abuse should control for the effects of gender-specific neurotoxicity.