Biology subjects

Abdulla, Z.

Publications and source records attributed to Abdulla, Z..

2 recordsLinked to original sources

bioRxiv2019

Creatine transporter knockout mice (Slc6a8) show increases in serotonin-related proteins and are resilient to learned helplessness

Approximately 20% of adults in the U.S. will experience an affective disorder during their life. While it is well established that serotonin (5-HT) is a crucial factor in mood, impaired cellular bioenergetics are also implicated. Creatine (Cr), through the Cr/Phospho-Cr (PCr) shuttle, maintains high ATP concentrations in the neuron. This system may be implicated in the etiology of affective disorders, as reduced Cr, PCr, and ATP are often seen in the brains of affected patients. To address this issue, Cr transporter (Crt) deficient male mice (Slc6a8-/y) and female mice heterozygous for Crt expression (Slc6a8+/-) were used to evaluate how a Cr deficient system would alter affective-like behaviors. Slc6a8-/y and Slc6a8+/- mice had more escapes and faster escape latencies in learned helplessness, indicating a potential resilience to behavioral despair. Elevated zero maze and tail-suspension test performance matched that of wildtype mice, however. Slc6a8-/y mice have increased 5-hydroxyindoleacetic acid content in the hippocampus and striatum and increased monoamine oxidase protein and tryptophan hydroxylase-2 protein content in the hippocampus, while serotonin levels are unchanged. This indicates an increase in 5-HT turnover. Our results indicate that Cr plays a complex role in affective disorders and 5-HT neurotransmission, warranting further investigation.

animal behavior and cognition↗

bioRxiv2019

Deletion of the creatine transporter gene in neonatal, but not adult, mice lead to cognitive deficits.

Creatine (Cr) is a guanidino compound that provides readily-available phosphate pools for the regeneration of spent ATP. The lack of brain Cr causes moderate to severe intellectual disability, language impairment, and epilepsy. The most prevalent cause of Cr deficiency are mutations in the X-linked SLC6A8 (Creatine transporter; CrT) gene, known as CrT deficiency (CTD). There are no current treatments for CTD and the mechanisms that underlie the cognitive deficits are poorly understood. One of the most critical areas that need to be addressed is if Cr is necessary for brain development. To address this concern, the Slc6a8 gene was knocked out in either neonatal (postnatal day (P)5) or adult (P60) mice. The P5 knockout mice showed deficits in the Morris water maze and novel object recognition, while there were no deficits in P60 knockout mice. Interestingly, the P5 knockout mice showed hyperactivity during the dark phase; however, when examining control mice, the effect was due to the administration of tamoxifen from P5-10. Taken together, the results of this study show that Cr is necessary during periods of brain development involved in spatial and object learning. This study also highlights the continued importance of using proper control groups for behavioral testing.\n\nTake-home messageThe learning and memory deficits seen in Slc6a8-deficient mice are likely due to the developmental loss of Cr.

neuroscience↗