Abnormal Relationship Between Medial Temporal Lobe and Subcortical Dopamine Function in People With an Ultra High Risk for Psychosis

Abstract

An altered relationship between MTL function and dopamine storage/synthesis capacity exists in the ARMS and may be related to psychosis vulnerability.

Do Subjects at Clinical High Risk for Psychosis Differ from those with a Genetic High Risk? - A Systematic Review of Structural and Functional Brain Abnormalities

“…Additionally, prefrontal brain activation was associated negatively and temporohippocampal activation was associated positively with thalamic glutamate levels in high-risk individuals [62]. Hippocampal activation in ARMS, but not in HC, was positively correlated with striatal dopamine function [65] and with medial temporal glutamate levels [66].…”

“…Functional studies of C-HR subjects [27,32,38,[46][47][48][49][50][51][52][53][54][55][56][57][58][59][61][62][63][64][65][66][67] are characterized in the Table 3 and results are summarized in the Table 5. We included 24 functional imaging studies and divided them according to the center where the population was studied.…”

“…It helps us better understand which studies had overlap and tested the same or very similar population of subjects with another functional paradigm. Most of the studies were carried out in London (9 fMRI and 6 multimodal [46][47][48][49][50][51][52][53][54][61][62][63][64][65][66]), two in Aachen [58,59], three in different centers in the USA [55][56][57], and in other centers in Europe and in Korea [27,32,38]. Two studies based on the same population were longitudinal [53,54] and 8 included FEP group as well (4 of them were based on the same population [49][50][51][52] and 4 were not [27,38,57,67]).…”

“…Altered activation in middle frontal gyrus and in parahippocampal gyrus correlated with striatal dopamine release [64]. Overt verbal fluency [61,62] and verbal encoding and recognition [65,66] tasks were evaluated in conjunction with additional PET and MRS data. ARMS individuals showed positive correlation between inferior frontal brain activation and pre-synaptic striatal dopamine dysfunction [61].…”

Abnormal Striatal Dopamine Transmission in Schizophrenia

“…Abnormalities in the AST have also been reported using F-DOPA uptake in ARMS ([29; for a negative result see also [31]), These findings have challenged the notion that in schizophrenia, alterations in subcortical DA transmission are most prominently localized to the ventral part and highlighted the potential role of the AST in the illness. This striatal region receives prominent input from the dorso lateral PFC, and is thought to play an important role in regulating the circuitry from various cortical regions.…”