Department of Psychiatry, University of California San Diego, La Jolla, CA, 2093, USA; VA Research Service, USA; VA Mental Illness Research, Education, and Clinical Center, VA San Diego Healthcare System, San Diego, CA, USA.
2 papers in the library · 25 citations · publishing 2020-2025
Activating serotonin 2A (5-HT2A) receptors impairs behavioral flexibility in male mice, as measured by a probabilistic reversal learning task. The selective 5-HT2A agonist 25CN-NBOH increased the number of trials needed to reach criterion during reversal learning, while the broader agonist DOI alone did not. However, combining DOI with a 5-HT2C receptor antagonist (SER-082) also impaired reversal learning, suggesting that 5-HT2A and 5-HT2C receptors have opposing effects on this aspect of executive function. All groups performed similarly on the initial spatial discrimination, indicating that the impairment was specific to adapting to changing contingencies.
In mice with reduced Sp4 expression, a gene linked to schizophrenia in humans, restoring Sp4 in young adults partially corrected two schizophrenia-related behavioral deficits—prepulse inhibition and hypersensitivity to ketamine—but did not improve context memory. The SP4 gene is strongly associated with schizophrenia risk; human studies show that loss of one copy increases odds of schizophrenia by about 9-fold. These results suggest that Sp4 restoration in adulthood may reverse some but not all behavioral abnormalities, supporting further investigation of SP4 as a potential drug target.