Reduced K+ Channel Inactivation, Spike Broadening, and After-Hyperpolarization in Kvβ1.1-Deficient Mice with Impaired Learning

A-type K⁺ channels are known to regulate neuronal firing, but their role in repetitive firing and learning in mammals is not well characterized. To determine the contribution of the auxiliary K⁺ channel subunit Kvβ1.1 to A-type K⁺ currents and to study the physiological role of A-type K⁺ channels in repetitive firing and learning, we deleted the Kvβ1.1 gene in mice. The loss of Kvβ1.1 resulted in a reduced K⁺ current inactivation in hippocampal CA1 pyramidal neurons. Furthermore, in the mutant neurons, frequency-dependent spike broadening and the slow afterhyperpolarization (sAHP) were reduced. This suggests that Kvβ1.1-dependent A-type K⁺ channels contribute to frequency-dependent spike broadening and may regulate the sAHP by controlling Ca²⁺ influx during action potentials. The Kvβ1.1-deficient mice showed normal synaptic plasticity but were impaired in the learning of a water maze test and in the social transmission of food preference task, indicating that the Kvβ1.1 subunit contributes to certain types of learning and memory.     

Modulator and filter circuits for EEG biofeedback

Inexpensive designs for two components of an EEG biofeedback system are described. A two-channel modulator accepts a pair of input signals for modulation of two audio carrier frequencies a musical fifth apart. Carrier suppression is obtained with a simple balanced modulator circuit for each channel. The filter circuit is an integrated circuit adaptation of a successful vacuum tube design reported by other investigators a number of years ago. Various configurations of this equipment for two-channel EEG biofeedback are described.     

Zitierte zeichenreihen

We use quotation marks when we wish to refer to an expression. We can and do so refer even when this expression is composed of characters which do not occur in our alphabet. That's why Tarski's, Quine's, and Geach's theories of quotation don't work. The proposals of Davidson, Frege, and C. Washington, however, do not provide a plausible account of quotation either. The problem is to construct a Tarskian theory of truth for an object language which contains quotation marks, without appealing to quotation marks in the metalanguage. I propose to supply Tarski's truth definition with an axiom which determines the denotation of all expressions containing quotation marks. According to this axiom, quotation marks create a non-extensional context. Since our admitting such contexts does not lead to any difficulties in our recursive truth characterization, we may indeed dispense with extensionalism. Finally, I argue that we classify and denote expressions in the very same way that we classify and denote extralinguistic entities.     

The Contemporary Constructive Task

Lutheran theology is noted for its excellent contributions to historical theology. Contemporary times, however, require that Lutheran theologians become attuned to the urgent demands of the present and take up the discipline of constructive theology to address these demands. Taking the lead from contemporary feminist Lutheran theologians, constructive approaches utilizing Lutheran theological resources must articulate vigorous critique of a corrosive neo‐liberal culture by articulating divine judgment on human greed as well as witnessing to divine grace that always favors truthful living.     

Preliminary evidence for a fronto‐parietal dysfunction in able‐bodied participants with a desire for limb amputation

Background. Reports of able‐bodied participants with the persisting desire for limb amputation raise legal and ethical questions that are partly due to insufficient empirical knowledge about the condition. Here, we searched for potential neurological mechanisms in participants with desire for limb amputation in order to help develop adequate nosological classifications, diagnosis, and treatment. Methods. Semi‐structured interviews were carried out with 20 participants who self‐identified themselves as able‐bodied individuals desiring amputation of a limb. Results. The results suggest that amputation desire is not unspecific, but in most cases specific for a circumscribed part of the body. Most frequently affected was the leg, mostly on the left, non‐dominant side. Left‐sidedness and limb specificity was associated with elementary and complex somatosensory disturbances of the affected limb akin to those reported by neurological patients. The most frequent neurological co‐morbidity was migraine headache. Conclusions. These results document the existence of an unusual condition in able‐bodied participants characterized by a person's desire for the amputation of one or more particular limbs. Left‐sidedness, limb specificity and somatosensory disturbances of the affected limb are suggestive of abnormal brain mechanisms in right fronto‐parietal cortex. Based on this association we suggest that desire for limb amputation may be conceptualized as asomatognosia due to disturbed integration of multi‐sensory information of the affected body parts into a coherent cerebral representation of the own body. This suggestion has to be regarded with caution as we did not perform any neurological examination.     

The mental time line: An analogue of the mental number line in the mapping of life events

A crucial aspect of the human mind is the ability to project the self along the time line to past and future. It has been argued that such self-projection is essential to re-experience past experiences and predict future events. In-depth analysis of a novel paradigm investigating mental time shows that the speed of this “self-projection” in time depends logarithmically on the temporal-distance between an imagined “location” on the time line that participants were asked to imagine and the location of another imagined event from the time line. This logarithmic pattern suggests that events in human cognition are spatially mapped along an imagery mental time line. We argue that the present time-line data are comparable to the spatial mapping of numbers along the mental number line and that such spatial maps are a fundamental basis for cognition.     

Clinical Differences Exist Between Patients Fulfilling the 1988 and 1994 Case Definitions of Chronic Fatigue Syndrome

Despite the existence of 2 different case definitions for chronic fatigue syndrome, little data exist to evaluate how each performs. We evaluated the symptom patterns of patients fulfilling either the more demanding 1988 or the less demanding 1994 case definitions of Chronic Fatigue Syndrome over an 11-year period from 1991 to 2001. Factor analysis identified 3 factors: muscular–skeletal, viral, and sleep:memory symptom factors accounting for significant variation in the data. Further discriminant analysis showed that the first 2 factors and a self-reported measure of decrease in activity alone gave 91% accuracy in the placement of patients into their respective case definitions. This analysis did indicate that both case definitions were capturing the same broad group of patients. However, the patients in the 1994 group do not endorse infectious-type symptoms as often or to the same degree of severity as those in the 1988 group. This may mean that infection as a cause of CFS is more likely in patients fulfilling the earlier, more demanding case definition.