Stereological study of pyramidal neurons in the human superior temporal gyrus from childhood to adulthood

Abstract

The association cortex of the superior temporal gyrus (STG) is implicated in complex social and linguistic functions. As such, reliable methods for quantifying cellular variation in this region could greatly benefit researchers interested in addressing the cellular correlates of typical and atypical function associated with these critical cognitive abilities. To facilitate this task, we first present a general set of cytoarchitectonic criteria targeted specifically toward stereological analyses of thick, Nissl stained sections for the homotypical cortex of the STG, referred to, here, as BA22/TA. Secondly, we use the optical fractionator to estimate pyramidal neuron number and the nucleator for pyramidal somal and nuclear volume to investigate the influence of age and sex on these parameters and to set a typically developing baseline for future comparisons. In 11 typically developing cases aged 4-48 years, the most distinguishing features of BA22/TA were the presence of distinct granular layers, a prominent, jagged layer IIIc, and a distinctly staining VIa. The average number of neurons was 91 ± 15 million, volume of pyramidal soma, 1,512 μm3, and nuclear volume, 348 μm3. We found no correlation with age and neuron number. In contrast, pyramidal somal and nuclear volume were both negatively correlated and linearly associated with age in regression analyses. We found no significant sex differences. Overall, the data support the idea that postnatal neuron numbers are relatively stable through development but also suggest that neuronal volume may be subject to important developmental variation. Both measures are critical variables in the study of developmental neuropathology.

White Matter Neurons in Young Adult and Aged Rhesus Monkey

“…For soma size, superficial WMNs neurons in FC and Par were larger in young adult monkeys. In contrast, Barger et al ( 2015 ), reported that pyramidal neuron soma and nuclear volume are reduced with age in human temporal areas. This could be a species difference, a gray- white-matter difference in the age-response or difference in the regions sampled.…”

“…This result is consistent with other studies, where no cell loss could be found with normal aging. In addition to multiple studies of cortical gray matter (for NHP: Hof et al, 2000 ; Giannaris and Rosene, 2012 ; and for human temporal cortex: Barger et al, 2015 ), several studies of human WMNs reported no cell loss in aged subjects. García-Marin et al ( 2010 ), using Neu-N IHC comparable to the present investigation, reported no correlation between age and density of WMNs in their survey in postmortem human white matter beneath areas 10, 17/18, 20, and 24; but only three of their 23 specimens were over 45 years old.…”

Neuron numbers increase in the human amygdala from birth to adulthood, but not in autism

“…Detailed descriptions of tissue processing are available in previous studies from cohort 1 ( 31 ) and cohort 2 ( 49 , 50 ) and in SI Experimental Procedures .…”

Specific Regional and Age-Related Small Noncoding RNA Expression Patterns Within Superior Temporal Gyrus of Typical Human Brains Are Less Distinct in Autism Brains

“…Samples were taken from the same coronal section in the posterior portion of the temporal lobe in each brain. PAC was taken from the crown of Heschl gyrus, where it is identified on both cytoarchitectonic and functional maps, 27 and the STS was taken from the dorsal, upper wall of the STS immediately opposite the Heschl gyrus 21 , 28 (see Figures 1 and 2 ).…”