Performance of normal and neurological mutant mice on radial arm maze and active avoidance tasks

The objectives of the present study are to assess the import of gene-imposed structural alterations on behavioral performance and obtain performance data preliminary to studies of experimental mouse chimera behavior. Reeler, staggerer, and weaver neurological mutant, and control B6C3 and ichthyosis mice were tested on radial arm maze and active avoidance tasks. Weaver mice had incapacitating seizures while performing the radial arm maze task and were, therefore, removed from further testing. Staggerer mice displayed a significant deficit on both tasks compared to control mice. Homozygous reeler mice (rl/rl) also had a significant deficit on the active avoidance task compared to +/rl control mice but not significantly poorer than ichthyosis mice. However, their performance on the radial arm maze task, while initially poor, improved so that they performed the task similar to wild-type controls. Three of the reeler mice reached criterion for solving the radial arm maze task. None of the staggerer mice reached criterion. These data are discussed in terms of the value of using neurologically mutant mice in dissecting structural-functional relationships. It is suggested that the behavior of these mutants might point toward specific components of cerebellar involvement in behavioral acts.     

Central nervous system manifestations in patients with systemic lupus erythematosus. Review of pathogenetic aspects

CNS manifestation is considered as a diagnostic as well as prognostic important variation of SLE course. Disturbances of blood flow and immunopathologic process participate in its induction. Antineuronal antibodies and circulating immune complexes in liquor show tight relations to CNS involvement.     

A computerized system for monitoring and controlling intracranial electrical self-stimulation behavior

An automated system for measuring intracranial self-stimulation behavior is described. The system consists of two Commodore 6502 microcomputers interfaced with a constant-current generator and a standard operant chamber. The system hardware allows sine- and square-wave stimulation. Stimulus intensity can be varied in 256 steps between 0 and 100, 0 and 500, or 0 and 1,000 /µA. The system programs, which are written in machine language, allow the control of various schedules of reinforcement, the counting of operant responses and reinforcements, the measurement of interresponse intervals, and the storage of the data on disk. The software is designed for the determination of the threshold of reinforcement, on the basis of the titration of postreinforcement pauses caused by changeover in schedule control between concurrent continuous reinforcement and fixed ratio schedules.     

Endogenous and symptomatic schizophrenia. Wherein lies the difference?

It is the opinion of the present writer that endogenous and symptomatic schizophrenia are two completely different matters. By classical symptomatology it is impossible to establish the distinction in every individual case. Nevertheless, in not one of the published cases known to us did Bonhoeffer err in his diagnosis of the one or the other. Evidently he made use of additional characteristica gathered in practice, about which he himself may not always have been quite clear.     

A kinematic analysis of anticipatory coarticulation in the speech of anterior aphasic subjects using electromagnetic articulography

An investigation was made into the extent and time course of anticipatory coarticulation in the speech of two normal and two anterior aphasic, German-speaking subjects. Both labial and velar coarticulation gestures were investigated. Subjects produced sentences containing target words contrasting in postconsonantal vowel rounding (e.g., [geli:ge]/[gely:gel]) and in nasality (e.g., [ti:de]/[ti:ne]). Speech kinematics were monitored by means of electromagnetic articulography. The data revealed that for correct productions, aphasic speakers' coarticulatory patterns were more highly variable than those of control subjects. These differences, however, were found chiefly for spatial displacement characteristics, while the temporal aspects of articulator movement necessary for anticipatory coarticulation appeared largely intact. Articulator mistiming did not appear to explain a small corpus of stop/nasal substitution errors produced by one of the aphasic speakers.     

The neurocognitive basis of autism

The cognitive study of the underlying mental abnormalities in autism has advanced rapidly, while the biological study of the underlying brain abnormalities and of putative genetic mechanisms is lagging somewhat behind. However, the linking of cognitive and biological studies has become a real possibility. Developmental cognitive neuroscience has transformed our understanding of this enigmatic disorder, which was once misguidedly thought to be caused by maternal rejection. The hypothesis of a specific theory of mind deficit was a crucial step in this process. It explains the puzzle of the characteristic social and communication impairments of autism and allows for the fact that they can coexist with good general abilities. This hypothesis has been widely accepted and a start has been made at pinpointing the brain basis of theory of mind. The non-social impairments of autism have now become a major focus for cognitive research. One theory proposes dysfunction in executive processes, in an attempt to explain repetitive behaviour and inflexibility. Another theory proposes weak information integration, in an attempt to explain narrow interests and special talents. Autism research has thus stimulated ideas on important mind-brain systems that may be dedicated to the development of social awareness, executive functions and integrative processing.