In vitro neuronal network activity in NMDA receptor encephalitis

Area of Science:

• Neuroimmunology
• Neuroscience
• Autoimmune Diseases

Background:

• Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe autoimmune disorder.
• Characterized by psychosis, seizures, and autonomic dysfunction, it primarily affects young women.
• Often associated with ovarian teratomas, NMDAR encephalitis involves antibodies targeting the NMDAR.

Purpose of the Study:

• To investigate the effects of patient cerebrospinal fluid (CSF) from an anti-NMDAR encephalitis patient on in vitro neuronal network activity (ivNNA).
• To explore how CSF from affected patients influences neuronal function and network dynamics.

Main Methods:

• Utilized a microelectrode array (MEA) system to record ivNNA from dissociated primary rat cortical neurons.
• Collected and applied patient CSF (pCSF) from different disease stages (acute and recovery) to neuronal cultures.
• Analyzed global spike/burst rates and network synchrony.

Main Results:

• CSF from the acute phase of anti-NMDAR encephalitis suppressed global spike and burst rates of ivNNA.
• CSF collected after clinical recovery and reduced antibody titers did not show this suppressive effect.
• Network synchrony remained unaltered, indicating selective effects on neuronal activity parameters.

Conclusions:

• Patient CSF directly suppresses global neuronal network activity in vitro.
• NMDAR antibodies selectively modulate specific parameters of neuronal network activity, not functional connectivity.
• Assessing ivNNA offers a potential new method to evaluate functional changes in autoimmune encephalitis.