Temporolimbic or Transcallosal Connections: Where Is the Primary Lesion in Schizophrenia and What Is Its Nature?

Abstract

A critique of the article by Bogerts on the temporolimbic system theory is presented. Schizophrenia is conceived as arising as a component of the diversity of interhemisphric (callosal) connectivity associated with the evolution of language, a process that occurred through a genetic change (the speciation event) that allowed the hemispheres to develop with a degree of independence. Language and psychosis thus have a common evolutionary origin. The anatomical changes can be considered as a boundary component of the anatomical variation that is characteristic of the species.

Callosal Abnormalities Across the Psychosis Dimension: Bipolar Schizophrenia Network on Intermediate Phenotypes

“…Our observations of reductions in the anterior splenial volume are consistent with previous results from the BSNIP group showing hippocampal and sub-region volume decrements psychosis probands and their relatives across diagnoses (54, 55). Such alterations could result in decreased or aberrant information flow between the medial temporal structures, parietal cortices, hippocampi and the subfields (35); this interhemispheric hypoconnectivity may be related to abnormal information processing, a core abnormality of these illnesses (14, 56). …”

Dysfunction of transcallosally mediated motor inhibition and callosal morphology in patients with schizophrenia

“…CC has been suspected to play a role in psychosis since the 19th century, when Wigan (2) proposed it as the 'seat of insanity'. Schizophrenia has been conceived as arising as a component of the diversity of interhemispheric (callosal) connectivity associated with the evolution of language, a process that occurred through a genetic change that allowed the hemispheres to develop with a degree of independence (3). Disruption of transcallosal connectivity could contribute to some of the cognitive disturbances associated with schizophrenia (4).…”

1910s' brains revisited. Cortical complexity in early 20th century patients with intellectual disability or with dementia praecox

“…Currently, analyses derived from structural magnetic resonance imaging (MRI) have confirmed morphometry and volume abnormalities in schizophrenia patients , and significant changes in gross neuroanatomy with multiple absent, duplicated or misshapen gyri . These changes in cortical folding features have been measured through sulcal index or gyrification index (GI) .…”