Direct interhemispheric cortical communication via thalamic commissures: a new white matter pathway in the primate brain

Cortical neurons of eutherian mammals project to the contralateral hemisphere, crossing the midline primarily via the corpus callosum and the anterior, posterior, and hippocampal commissures. We recently reported and named the thalamic commissures (TCs) as an additional interhemispheric axonal fiber pathway connecting the cortex to the contralateral thalamus in the rodent brain. Here, we demonstrate that TCs also exist in primates and characterize the connectivity of these pathways with high-resolution diffusion-weighted MRI, viral axonal tracing, and fMRI. We present evidence of TCs in both New World (Callithrix jacchus and Cebus apella) and Old World primates (Macaca mulatta). Further, like rodents, we show that the TCs in primates develop during the embryonic period, forming anatomical and functionally active connections of the cortex with the contralateral thalamus. We also searched for TCs in the human brain, showing their presence in humans with brain malformations, although we could not identify TCs in healthy subjects. These results pose the TCs as a vital fiber pathway in the primate brain, allowing for more robust interhemispheric connectivity and synchrony and serving as an alternative commissural route in developmental brain malformations.

Clarifying and extending our understanding of problematic pornography use through descriptions of the lived experience

Problematic pornography use (PPU) is a complex and growing area of research. However, knowledge of the PPU lived experience is limited. To address this gap, we conducted an online qualitative study with 67 individuals who self-identified as having problematic pornography use (76% male; Mage = 24.70 years, SD = 8.54). Results indicated several dimensions that have not been fully explored in the literature. These included various mental and physical complaints following periods of heavy pornography use, sexual functioning deficits with real partners, and a subjectively altered state of sexual arousal while using pornography. Moreover, we expanded on current knowledge regarding the inner conflict associated with PPU and clarified the ways that users can progress to increasingly intensified patterns of pornography use, such as tolerance/escalation and pornographic binges. Our study highlights the complex and nuanced nature of PPU and provides suggestions for future research and clinical practice.

Concealing, Tolerating, and Adjusting to Emotions in Obsessive-Compulsive and Anxiety Disorders: A Cross-Sectional Study

BACKGROUND

Although research has shown that mood and anxiety disorders manifest disturbed emotion regulation, it is unclear whether anxiety disorders differ between each other in terms of their emotion regulation strategies. In the present study, we investigated whether patients with anxiety disorders present different affective styles.

METHODS

We assessed affective styles of 32 obsessive-compulsive disorder (OCD) patients, 29 social anxiety disorder (SAD) patients, 29 panic disorder (PD) patients, and 20 healthy controls through the Affective Style Questionnaire (ASQ). A multivariate analysis of covariance (MANCOVA) was performed to compare the affective styles across groups (OCD, SAD, PD and control), while controlling for depression, anxiety symptoms and age.

RESULTS

The MANCOVA revealed a significant, small-medium, main effect of diagnostic group on affective styles. The planned contrasts revealed that OCD and SAD patients reported significantly lower scores for "tolerance" (ASQ-T) compared to healthy controls group. There were no differences between PD group and healthy controls.

CONCLUSIONS

Our findings provide evidence that OCD and SAD have difficulty tolerating strong emotions existing in the present moment in an open and non-defensive way.