Inversion of the hemispheric laterality of the anterior cingulate gyrus in schizophrenics.

The anterior cingulate gyrus (acg) is involved in mechanisms of attention and emotion, where the right hemisphere is considered to be dominant. One of the models for neuropsychological dysfunction in schizophrenia suggests an impairment in the balance of lateralized functions. Fourteen adult human female brains, having no macroscopic lesions, were used in this study. Seven brains came from female patients with clinical diagnoses of residual schizophrenia (DSM-III-R; APA 1987). Seven female brains were used as controls. Thirteen male brains were also studied, with the sole purpose of establishing the typicality of the female controls. All schizophrenic brains were age matched with control brains. Right laterality for weight (71.4%) and surface (85.7%) was observed in the acg of female control brains. The inversion of this laterality in a significant number of the schizophrenic cases was the most relevant finding in this study.

[Morphological changes of the corpus callosum in schizophrenia]. / Alteraciones morfológicas del corpus callosum en esquizofrénicos.

Morphological brain alterations have long been noted in schizophrenia, although it is unclear whether they are a consequence of an early disturbance in brain development or represent a deterioration of a normal brain structure. The purpose of the present study is to establish a relationship between corpus callosum (CC) surface and perimeter. A female right handed schizophrenic group (n = 31) was compared with a control group (n = 25) of comparable sex, age (range: 40-68 years) and handedness on measures of the CC area from a midsagittal T1 weighted image magnetic resonance imaging. Patients completed DSM IV criteria for Residual Schizophrenia. Patients with a known history of brain injury or neurologic illness were excluded. All had received neuroleptic drugs but no electroconvulsive treatment. Control and schizophrenic groups were subdivided into two age-ranges (E1 < or = 54 years and E2 > 54 years). Mean +/- SE (cm2) of CC surface in controls E < or = 54 and E > 54 were respectively 7.09 +/- 0.42 and 8.97 +/- 0.62 (p < 0.01) and in schizophrenics E < or = 54 and E > 54 were respectively 7.61 +/- 0.24 and 6.60 +/- 0.29 (p < 0.05). Among control and schizophrenic E > 54 sub-groups there were significant differences (p < 0.01). Statistically significant differences among sub-group values were obtained through analysis of variance. Correlation coefficient (r) between age and surface in control and schizophrenic groups were respectively 0.55; p < 0.05 and -0.45; p < 0.02. Our results provide evidence that chronic female schizophrenic patients have diminished CC surface and altered proportionality among surface and perimeter, that increases with age. However, in the control group, there is an increment of corpus callosum surface without altered perimeter proportionality.

Simple spiral nerve endings in human extraocular muscles.

The goal of this paper is to describe the presence and morphology of simple spiral nerve endings as well as their distribution within the extraocular muscles of the human being. The extraocular muscles of four male subjects were dissected out and stained with several silver impregnation methods. The results obtained showed the presence of nerve endings that surround muscle fibers and correspond to the classification of simple spiral nerve endings by Daniel (1946). However they were found to differ in size from this description. They were distributed throughout the entire body of the muscles, although they appeared to be more abundant in the proximal third. Most of these endings encircled between two and four times the muscles fibers. The nerve fiber forming the spirals were surrounded by a capsule of connective tissue which appears to keep the fibers attached to the muscles. The fact that proprioceptors may adopt different morphological shapes suggests that proprioception may be conformed of different components, one of which may be mediated by simple spiral nerve endings.