Correspondence between neural process and frontal lobe gyri on coronal sections / 局解手术学杂志

Objective To explore the corresponding rules between neural process and frontal lobe gyri and provide anatomic basis for locating frontal lobe gyri by neural process. Methods 20 normal cadaver heads were transected into brain slices with thickness of 6 mm after dyeing frontal lobe gyri. Typical planes were observed,while the correspondence between neural process and frontal lobe gyri on coronal sec-tions were analyzed and summarized. Results There was 1 or 2 processes for almost frontal lobe gyri,with the direction of neural process in different coronal sections being unchanged and symmetric. Conclusions The corresponding rules between neural processes and frontal lobe gyri may be obtained and the frontal lobe gyri on coronal sections may be located through neural processes.

Supratentorial Dissection of the Human Brain for Neuroscientists.

Background: Recent clinical advancements, including brain imaging or target specific procedures, have increased the demand for a more advanced understanding of the structure of the brain. The need for a more sophisticated, functionally relevant understanding the structure of the brain has resulted in a surge of neuroanatomy dissection courses, including gross neuroanatomical observation, cross-sectioning, blunt dissection and various fiber dissection techniques. Methods: Sixteen (16) adult, formalin fixed cerebral hemispheres were included in this study. Surface anatomy, blunt dissection of the lateral ventricles, and cross-sectioning of the anterior portion of the hemisphere, was performed on all specimens. Results: A detailed, but simplified, protocol consisting of seven steps is proposed for the study of the supratentorial anatomy of the human brain. The first two steps promote an appreciation of the predominate structural pattern of the surface of the brain. Four distinct, consecutive dissection steps are recommended for the dissection of the ventricular system. Horizontal cross-sectioning of the anterior portion of the hemisphere is described in five sub-steps. Conclusion: Dissection methods described provides an appreciation of the predominate structural pattern of the surface of the brain, in relation to the deep the structures. This appreciation is gained through the step-by-step dissection of the ventricular system and cross-sections. In addition to understanding the surface-to-deep relationships, the hands-on practical study of the anatomy of brain as described herein, allows the observer to gain a true three-dimensional structural understanding of the human brain.

Reduced Gray Matter Volume of Auditory Cortical and Subcortical Areas in Congenitally Deaf Adolescents: A Voxel-Based Morphometric Study

PURPOSE: Several morphometric studies have been performed to investigate brain abnormalities in congenitally deaf people. But no report exists concerning structural brain abnormalities in congenitally deaf adolescents. We evaluated the regional volume changes in gray matter (GM) using voxel-based morphometry (VBM) in congenitally deaf adolescents. MATERIALS AND METHODS: A VBM8 methodology was applied to the T1-weighted magnetic resonance imaging (MRI) scans of eight congenitally deaf adolescents (mean age, 15.6 years) and nine adolescents with normal hearing. All MRI scans were normalized to a template and then segmented, modulated, and smoothed. Smoothed GM data were tested statistically using analysis of covariance (controlled for age, gender, and intracranial cavity volume). RESULTS: The mean values of age, gender, total volumes of GM, and total intracranial volume did not differ between the two groups. In the auditory centers, the left anterior Heschl's gyrus and both inferior colliculi showed decreased regional GM volume in the congenitally deaf adolescents. The GM volumes of the lingual gyri, nuclei accumbens, and left posterior thalamic reticular nucleus in the midbrain were also decreased. CONCLUSIONS: The results of the present study suggest that early deprivation of auditory stimulation in congenitally deaf adolescents might have caused significant underdevelopment of the auditory cortex (left Heschl's gyrus), subcortical auditory structures (inferior colliculi), auditory gain controllers (nucleus accumbens and thalamic reticular nucleus), and multisensory integration areas (inferior colliculi and lingual gyri). These defects might be related to the absence of general auditory perception, the auditory gating system of thalamocortical transmission, and failure in the maturation of the auditory-to-limbic connection and the auditorysomatosensory-visual interconnection.