Abstract. Ketamine produces fast-acting antidepressant effects in treatment resistant depression (TRD). Prior studies have shown altered functional dynamics between brain networks in major depression. We thus sought to determine whether functional brain network dynamics are modulated by ketamine therapy in TRD. Participants with TRD (n=58, mean age=40.7 years, female=48.3%) completed resting-state fMRI scans and clinical assessments (mood and rumination) at baseline and 24 h after receiving four ketamine infusions (0.5mg/kg) over two weeks. Healthy controls (HC) (n=56, mean age=32.8 years, female=57.1%) received the same assessments at baseline and after two weeks in a subsample without treatment. A co-activation pattern (CAP) analysis identified recurring patterns of brain activity across all subjects using k-means clustering. Statistical analyses compared CAP metrics including the fraction of time (FT) spent in a brain state, and the transition probability (TP) from one state to another over time and associations with clinical improvement. Follow-up analyses compared HC and TRD at baseline. Six brain state clusters were identified, including patterns resembling the salience (SN), central executive (CEN), visual (VN), default mode (DMN), and somatomotor (SMN) networks. Following ketamine, TRD patients showed decreased FT for the VN (p=7.4E-04) and increased FT for the CEN state (p=1.9E-03). For TP metrics, SN-CEN increased (p=5.8E-04) and SN-VN decreased (p=3.6E-03). Decreased FT for the SN associated with improved rumination (p=1.9E-03). At baseline, lower FT for CEN (p=5.70E-04) and TP for SN-CEN (p=0.016) and higher TP for SN-VN (p=2.60E-03) distinguished TRD from HCs. CAP metrics remained stable over time in a subsample of HCs (n=18). These findings suggest ketamine modulates brain network dynamics between SN, CEN and VN in TRD, which may normalize dynamic patterns seen in TRD at baseline towards patterns seen in controls. Changes in SN state dynamics may correspond to improvements in ruminative symptoms following ketamine therapy.

But the agency has spent nearly its entire budget for this fiscal year, which ends tomorrow.

A San Francisco-based federal judge on Monday ordered the Trump administration to restore all National Institutes of Health grants to UCLA, roughly $500 million, that the government suspended in July.

University of California faculty, students and staff on Tuesday sued President Trump over a $1.2-million penalty against UCLA and federal demands over campus changes. They argued that the actions camp...

These partnerships accelerate neuroscience by enabling researchers to share resources and expertise, as well as generate more relevant and reproducible results. But new federal funding restrictions in...

A federal judge on Tuesday ordered Trump administration to restore hundreds of frozen National Science Foundation research grants to UCLA.

As federal support vanishes for research addressing the root causes of health disparities in the United States, we are left with a dangerous void and an urgent need to rethink science funding.

We must stand together to protect our students, staff, faculty and our mission.

NIH Funding Opportunities and Notices in the NIH Guide for Grants and Contracts: Request for Information on Maximizing Research Funds by Limiting Allowable Publishing Costs NOT-OD-25-138. NIH