Determination of manganese valency in La1−xSrxMnO3 using ELNES in the (S)TEM

In this article several experimentally identified Mn valence-sensitive ELNES quantities for the La1-xSrxMnO3 compound class are presented, namely the energy separations between Mn-L3 and O-Ka, between O-Kb and O-Ka edges, the Mn-L2,3 white line intensity ratio, and the Mn-L3 line width. Valence sensitivities of these quantities are evaluated, and possible additional influences on them are considered. At high signal-to-noise ratio the two energy separations display most sensitively changes of the Mn valency. An experiment-based estimation of the total uncertainties of the quantities indicates that at low signal-to-noise ratio, which is the case when studying interface effects at high spatial resolution, again both energy separations allow to resolve the smallest valency changes.

Multiple kinetic states underlying macroscopic M-currents in bullfrog sympathetic neurons

M-current is a time- and voltage-dependent potassium current which is suppressible by muscarinic receptor activation. We have used curve fitting and noise analysis to determine if macroscopic M-currents deviate from a previously predicted simple two-state kinetic scheme. The M-current was best described by three kinetically distinct components: 'fast' (tau 0), 'intermediate' (tau 1) and 'slow' (tau 2) time constants. The 'fast' (tau 0) and 'intermediate' (tau 1) components were identified from the spectra of M-current noise at potentials positive to the cells' resting membrane potential. The 'intermediate' (tau 1) and 'slow' (tau 2) components were seen by curve fitting M-current deactivation currents. The 'intermediate' (tau 1) time constant was voltage dependent (decreasing e-fold in 23 mV), but voltage dependence of the 'fast' (tau 0) and 'slow' (tau 2) components was not obvious. All kinetic components were sensitive to muscarine, with the 'intermediate' (tau 1) and 'slow' (tau 2) being equally so. These data suggest that all components may derive from the same channel population, and that the M-channel may have at least four kinetic states.

Omega-conotoxin sensitivity and presynaptic inhibition of glutamatergic sensory neurotransmission in vitro

Synaptic transmission between embryonic chick dorsal root ganglion (DRG) neurons and spinal cord neurons was studied in dissociated cell culture. Stimulation of DRG neurons evoked monosynaptic and polysynaptic excitatory responses in the spinal neurons. These responses could be reversibly blocked by application of 6-cyano-7-nitroquinoxaline-2,3-dione (a selective non-NMDA receptor antagonist) and irreversibly eliminated through the presynaptic action of omega-conotoxin GVIA (a selective N-type calcium channel antagonist). As N-type calcium channels in DRG neuron somata are targets for modulation via GABAB receptors, we tested the role of these receptors as regulators of synaptic transmission. Baclofen (a selective GABAB receptor agonist) reversibly inhibited synaptic transmission via a presynaptic, pertussis toxin-sensitive mechanism; CGP 35348 (a selective GABAB receptor antagonist) blocked the actions of baclofen. Taken together, these results demonstrate that N-type calcium channels play a dominant role in glutamatergic sensory neurotransmission. They suggest, in addition, that modulation of N-channel activity may underlie, at least in part, presynaptic inhibition of synaptic transmission between DRG neurons and their targets in the intact spinal cord.

[Psychiatry in a country hospital in Freudenstadt, close to the patients' domicile. A critical preliminary review after three years (author's transl)]

The article reports on the setting-up of a department of psychiatry at the general hospital in the Freudenstadt district. The department comprises 60 beds and represents the first hospital-integrated psychiatric department of its kind of the Baden-Württemberg Land government. It was inaugurated in the summer of 1976. The experience collected over a period of 3 years, presented here in detail, can be made use of within the overall framework of the discussions on the controversial issue of psychiatric departments in general hospitals, which has also been discussed on a political plane.

[The problem of juvenile alcoholism. An analysis of the literature (author's transl)]

In contrast to drug addiction juvenile alcoholism now also common in West Germany, has hardly been investigated. This is meant to be an analysis of the literature, based mainly paper on German and American writings which the author tries to link to his own experience. The older papers from around the turn of the century are particularly evaluated. Essentially the following may be said: Transition between the use, misuse and dependence on alcohol is fluid, particularly in juvenile alcoholism. In our type of Society drinking in adolescence is part of an anticipatory socialization process and so a normal transitional phenomenon. More attention has lately been paid to influences arising in the primary group (family and peers). Girls tent to accept the traditions of the family more readily and follow in alcohol consumption more their mothers than their fathers. The epidemiologic papers published in German on drug addiction of juveniles can hardly be compared with each other, even if they take account of alcohol consumption. Individual control investigations on comparable populations during the last few years show an increase of excessive alcohol intake particularly among the young. In West Germany there are no reliable statistics on alcoholism in adults, even less in juveniles. The methodic difficulties in assessing prevalence of juvenile alcoholism are specific, but they mirror the general difficulties of definition in research into alcoholism. Clinical experience suggests that alcoholism runs a different course in juveniles--and in women--from that seen in adult men. Literature on juvenile alcoholism is sparse compared with that on drug addiction. The question of a correlation between primary alcoholism and drug-addiction - the role of alcohol as initiator to drugs - cannot be defined in general, only in individual terms. In drug addicts alcohol had and has the function of an addition to/or replecement for drugs. The alcohol problem started under the cover of drug addiction but without the preceding wave of drugs it would not have reached the present level...