[Are urban dwellers more depressed and anxious than the rural population? Results of a representative survey].

This study investigates the association between urbanicity and mental health in the general population. We conducted a representative survey (N = 5,036) measuring depression (PHQ-2), anxiety (GAD-2) as well as life satisfaction (FLZM). Results support the assumption that the prevalence rate for pathological scores of depression and anxiety are higher in urban than in rural areas.

Potassium channel dysfunction and depolarized resting membrane potential in a cell model of SCA3.

Spinocerebellar ataxia type 3 (SCA3) is an autosomal dominant inherited neurodegenerative disease caused by the expansion of a polyglutamine repeat within the disease protein, ataxin-3. There is growing evidence that neuronal electrophysiological properties are altered in a variety of polyglutamine diseases such as Huntington's disease and SCA1 and that these alterations may contribute to disturbances of neuronal function prior to neurodegeneration. To elucidate possible electrophysiological changes in SCA3, we generated a stable PC12 cell model with inducible expression of normal and mutant human full-length ataxin-3 and analyzed the electrophysiological properties after induction of the recombinant ataxin-3 expression.

Variable K(+) channel subunit dysfunction in inherited mutations of KCNA1.

Mutations of KCNA1, which codes for the K(+) channel subunit hKv1.1, are associated with the human autosomal dominant disease episodic ataxia type 1 (EA1). Five recently described mutations are associated with a broad range of phenotypes: neuromyotonia alone or with seizures, EA1 with seizures, or very drug-resistant EA1.

Human epilepsy associated with dysfunction of the brain P/Q-type calcium channel.

Background: The genetic basis of most common forms of human paroxysmal disorders of the central nervous system, such as epilepsy, remains unidentified. Several animal models of absence epilepsy, commonly accompanied by ataxia, are caused by mutations in the brain P/Q-type voltage-gated calcium (Ca(2+)) channel. We aimed to determine whether the P/Q-type Ca(2+) channel is associated with both epilepsy and episodic ataxia type 2 in human beings.

The inherited episodic ataxias: how well do we understand the disease mechanisms?

The past few years have seen the elucidation of several neurological diseases caused by inherited mutations of ion channels. In contrast to many other types of genetic disorders, the "channelopathies" can be studied with high precision by applying electrophysiological methods. This review evaluates the success of this approach in explaining the mechanisms of two forms of episodic ataxia that are known to be caused by mutations of ion channels: episodic ataxia type 1 (EA1, caused by K+ channel mutations) and episodic ataxia type 2 (EA2, caused by Ca2+ channel mutations).

Clinical, genetic, and expression studies of mutations in the potassium channel gene KCNA1 reveal new phenotypic variability.

Episodic ataxia type 1 (EA1) is an autosomal dominant central nervous system potassium channelopathy characterized by brief attacks of cerebellar ataxia and continuous interictal myokymia. Point mutations in the voltage-gated potassium channel gene KCNA1 on chromosome 12p associate with EA1. We have studied 4 families and identified three new and one previously reported heterozygous point mutations in this gene.

The molecular biology of the autosomal-dominant cerebellar ataxias.

Autosomal-dominant cerebellar ataxias (ADCA) may present as progressive or paroxysmal disorders. While the progressive ataxias have been named spinocerebellar ataxias (SCA), the paroxysmal disorders are designated episodic ataxias (EA). Until now, three different mutational mechanisms resulting in distinctive pathogenesis have been identified.

The origin of ocular microtremor in man.

A novel technique for the study of human eye movements was used to investigate the frequency components of ocular drift and microtremor in both eyes simultaneously. The tangential components of horizontal eye accelerations were recorded in seven healthy subjects using light-weight accelerometers mounted on scleral contact lenses during smooth pursuit movements, vestibulo-ocular reflexes and eccentric gaze with and without fixation. Spectral peaks were observed at low (up to 25 Hz) and high (60-90 Hz) frequencies.

A novel mutation in the human voltage-gated potassium channel gene (Kv1.1) associates with episodic ataxia type 1 and sometimes with partial epilepsy.

Episodic ataxia type 1 (EA1) is a rare autosomal dominant disorder characterized by brief episodes of ataxia associated with continuous interattack myokymia. Point mutations in the human voltage-gated potassium channel (Kv1.1) gene on chromosome 12p13 have recently been shown to associate with EA1.

A hyperprostaglandin E syndrome mutation in Kir1.1 (renal outer medullary potassium) channels reveals a crucial residue for channel function in Kir1.3 channels.

Loss of function mutations in kidney Kir1.1 (renal outer medullary potassium channel, KCNJ1) inwardly rectifying potassium channels can be found in patients suffering from hyperprostaglandin E syndrome (HPS), the antenatal form of Bartter syndrome. A novel mutation found in a sporadic case substitutes an asparagine by a positively charged lysine residue at amino acid position 124 in the extracellular M1-H5 linker region.

Subunit interactions in the assembly of neuronal Kir3.0 inwardly rectifying K+ channels.

Cardiac G protein-activated Kir (GIRK) channels may assemble as heterotetrameric polypeptides from two subunits, Kir3.1 and Kir3.4.

Functional expression and cellular mRNA localization of a G protein-activated K+ inward rectifier isolated from rat brain.

We have cloned by homology screening from a rat brain cDNA library a GIRK3-type (Kir 3.3) inwardly rectifying K+ channel subunit with high structural similarity to other subfamily members whose activity is thought to be controlled by receptor-stimulated G proteins. When heterologously expressed both in Xenopus oocytes and in mammalian COS-7 cells, rbGIRK3 subunits individually fail to form functional channels.

A G-protein-activated inwardly rectifying K+ channel (GIRK4) from human hippocampus associates with other GIRK channels.

Transcripts of a gene, GIRK4, that encodes for a 419-amino-acid protein and shows high structural similarity to other subfamily members of G-protein-activated inwardly rectifying K+ channels (GIRK) have been identified in the human hippocampus. When expressed in Xenopus oocytes, GIRK4 yielded functional GIRK channels with activity that was enhanced by the stimulation of coexpressed serotonin 1A receptors. GIRK4 potentiated basal and agonist-induced currents mediated by other GIRK channels, possibly because of channel heteromerization.