Resumen de Layer-specific reduced neuronal density in the orbitofrontal cortex of older adults with obsessive–compulsive disorder
Kátia Cristina de Oliveira, Lea Tenenholz Grinberg, Marcelo Queiroz Hoexter, Helena Brentani, Claudia Kimie Suemoto, Fabiano Gonçalves Nery, Luzia Carreira Lima, Ana Tereza Di Lorenzo Alho, Jose Marcelo Farfel, Renata Eloah de Lucena Ferreti-Rebustini, Renata Elaine Paraizo Leite, Ariane Cristine Moretto, Alexandre Valotta da Silva, Beny Lafer, Eurípedes Constantino Miguel, Ricardo Nitrini, Wilson Jacob-Filho, Helmut Heinsen, Carlos Augusto Pasqualucci
Neurobiological models have provided consistent evidence of the involvement of cortical–subcortical circuitry in obsessive–compulsive disorder (OCD). The orbitofrontal cortex (OFC), involved in motivation and emotional responses, is an important regulatory node within this circuitry. However, OFC abnormalities at the cellular level have so far not been studied. To address this question, we have recruited a total of seven senior individuals from the Sao Paulo Autopsy Services who were diagnosed with OCD after an extensive post-mortem clinical evaluation with their next of kin. Patients with cognitive impairment were excluded. The OCD cases were age- and sex-matched with 7 control cases and a total of 14 formalin-fixed, serially cut, and gallocyanin-stained hemispheres (7 subjects with OCD and 7 controls) were analyzed stereologically. We estimated laminar neuronal density, volume of the anteromedial (AM), medial orbitofrontal (MO), and anterolateral (AL) areas of the OFC. We found statistically significant layer- and region-specific lower neuron densities in our OCD cases that added to a deficit of 25% in AM and AL and to a deficit of 21% in MO, respectively. The volumes of the OFC areas were similar between the OCD and control groups. These results provide evidence of complex layer and region-specific neuronal deficits/loss in old OCD cases which could have a considerable impact on information processing within orbitofrontal regions and with afferent and efferent targets.
