title: Quantitative estimation of the primary auditory cortex in human brains.
abstract: Functional neuroimaging studies in humans are common worldwide. In order to determine with more accuracy both morphometric parameters and volume of the primary auditory cortex (PAC), we studied both right and left hemispheres in human control brains. Twelve hemispheres were systematically sectioned orthogonal to the anterior-posterior commissures (ac-pc line). Serial sections of the complete temporal lobe at 50 microm were obtained and stained with thionin (12 hemispheres) for cytoarchitectonic analysis. Four hemispheres were stained with the neuronal marker parvalbumin, a marker of primary sensory cortices. Morphometric analysis of the thionin-stained sections included size and shape factors as well as volume estimation using the Cavalieri method. Primary auditory areas extended for an average of 24 mm (twelve 2 mm apart sections); volume estimates determined by the Cavalieri method was 857+/-213 mm3 with a range of 658 mm3. The left primary auditory cortex was 7% greater than the right auditory cortex, without significant differences between hemispheres. The size and form of morphometric parameters obtained from each sampled section also revealed scarce differences between hemispheres, and the tendency to irregularity and ellipsoidity was more marked in the left hemisphere. No differences in size and form between right and left hemispheres were determined in our study. Morphometric analysis are of value in functional studies, specially those using non-invasive and lower resolution techniques such as Single Photon Emission Computed Tomography (SPECT).
authors.affiliation: Human Neuroanatomy Laboratory, Department of Health Sciences, School of Medicine and C.R.I.B., University of Castilla-La Mancha, Avda. de Almansa s/n, 02006 Albacete, Spain. Emilio.Artacho@uclm.es
authors.forename: Emilio
authors.initials: E
authors.lastname: Artacho-Pérula
authors.forename: Javier
authors.initials: J
authors.lastname: Arbizu
authors.forename: Maria del Mar
authors.initials: Mdel M
authors.lastname: Arroyo-Jimenez
authors.forename: Pilar
authors.initials: P
authors.lastname: Marcos
authors.forename: Alino
authors.initials: A
authors.lastname: Martinez-Marcos
authors.forename: Xavier
authors.initials: X
authors.lastname: Blaizot
authors.forename: Ricardo
authors.initials: R
authors.lastname: Insausti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001303:Auditory Cortex / Q000033:anatomy & histology* / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011180:Postmortem Changes; D013194:Staining and Labeling; D013238:Stereotaxic Techniques