GABAB receptor antibodies in paraneoplastic cerebellar ataxia.

Autoantibodies to the gamma-aminobutyric acid-B (GABAB) receptor were recently described in patients with limbic encephalitis presenting with early or prominent seizures. We report on a 64-year-old man with malignant melanoma who during adjuvant therapy with interferon (IFN)-alpha developed cerebellar ataxia. Indirect immunofluorescence on brain tissue sections revealed high-titer (1:20,000) IgG1 serum autoantibodies to the cerebellar molecular and granular layer, which were confirmed to be directed against GABAB receptor in a cell-based assay.

Central serotonin transporter levels are associated with stress hormone response and anxiety.

Rationale: Negative mood states are characterized by both stress hormone dysregulation and serotonergic dysfunction, reflected by altered thalamic serotonin transporter (5-HTT) levels. However, so far, no study examined the individual association between cortisol response and cerebral in vivo 5-HTT levels in patients suffering from negative mood states.

Objective: The objective of this cross-sectional study was to assess the interrelation of cortisol response, thalamic 5-HTT levels, and anxiety in healthy subjects and two previously published samples of patients with unipolar major depression (UMD) and obsessive-compulsive disorder (OCD), controlling for age, gender, 5-HTT genotype, smoking, and seasonality.

Imaging the deluded brain.

Various factors contribute to the development and maintenance of delusions in the context of schizophrenic psychoses. Studies with functional and structural MRI were able to detect neurobiological correlates of paranoid symptoms. Consistent with the neurodevelopmental hypothesis of schizophrenic psychosis, which implies an early developmental disorder affecting temporo-limbic areas and resulting in a disinhibition of striatal dopamine release, current imaging studies point towards the involvement of temporo-limbic and frontal dysfunction in delusion formation.