Tetrahydropalmatine, a compound with known analgesic and other pharmacological effects, protected against ketamine-induced learning and memory impairment in mice. In the Morris water maze and open field tests, tetrahydropalmatine treatment reduced escape latency and increased platform site crossings. It also lowered oxidative stress, inflammation, and acetylcholinesterase activity, and decreased acetylcholine levels. The treatment suppressed iNOS, caspase-3, caspase-9, nuclear factor-κB, glial fibrillary acidic protein, cytochrome c, and phospholipase C-γ1 protein expression, while increasing glial cell-derived neurotrophic factor. These findings suggest tetrahydropalmatine may counteract ketamine's cognitive side effects through antioxidative, anti-inflammatory, and anti-apoptotic mechanisms.
Auditory evoked potentials (AEPs), specifically the N100 component and the auditory steady-state response (ASSR), are used to assess patients with disorders of consciousness (DOC), but their relative value is debated. In 30 DOC patients, the ASSR response was a more reliable marker of auditory function than N100. However, neither N100 nor ASSR, at response or microstate levels, could effectively distinguish between patients with unresponsive wakefulness syndrome (UWS) and those in a minimally conscious state (MCS). The role of ASSR was validated using a portable EEG device in an independent cohort of 30 patients. ASSR shows promise for assessing auditory function in DOC patients, but its utility in differentiating levels of consciousness may require further consideration.