T-817MA, a neuroprotective agent, attenuates the motor and cognitive impairments associated with neuronal degeneration in P301L tau transgenic mice.

Tau pathology is implicated in mechanisms of neurodegenerative tauopathies, including Alzheimer's disease (AD) and hereditary frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). It has been reported that transgenic mice expressing FTDP-17 mutation P301L of human tau (P301L mice) display extensive tau pathology and exhibit behavioral deficits with aging. In this study, we investigated the effects of T-817MA, a neuroprotective agent, on the motor and cognitive impairments associated with neuronal degeneration in P301L mice. T-817MA prevented the progression of motor deficit and the loss of spinal cord motor neurons in P301L mice. Furthermore, T-817MA significantly attenuated the spatial memory impairment and the reduction in synaptic terminal density in the hippocampal dentate gyrus of P301L mice. These results indicate that T-817MA improved the motor and cognitive impairments as a result of inhibiting neuronal degeneration derived from tau pathology in the P301L mice. Therefore, it is expected that T-817MA has a therapeutic potential for tau-related neurodegenerative diseases such as AD.

Oral administration of a neuroprotective compound T-588 prevents motoneuron degeneration after facial nerve avulsion in adult rats.

OBJECTIVE: R(-)-1-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino) ethoxylethanol hydrochloride (T-588), a synthetic compound, has been shown to have neuroprotective potentials for neuronal cells. We investigated whether orally administered T-588 can rescue injured motoneurons after facial nerve avulsion in adult rats. METHODS: The right facial nerves of adult Fischer 344 male rats were avulsed and the animals were freely administered solution of 0.05% (w/v) T-588 or received T-588 (3-30 mg/kg/day) through an oral tube for 1-4 weeks. Facial motoneurons on both sides of the facial nuclei were counted in Nissl-stained sections, and choline acetyltransferase (ChAT) immunoreactivity in injured motoneurons and ChAT enzyme activities in the ventral brain stem tissue containing the facial nuclei were examined. RESULTS: Both free oral administration of 0.05% T-588 solution and oral tube administration of T-588 (30mg/kg/day) improved the survival of facial motoneurons at 3 or 4 weeks after avulsion. These treatments ameliorated ChAT immunoreactivity in injured motoneurons and the tissue ChAT enzyme activities at 1-week postoperation examined. CONCLUSION: These results indicate that oral administration of T-588 ameliorates the survival of injured motoneurons and supports their neuronal function after facial nerve avulsion in adult rats. T-588 may have therapeutic potential in motoneuron injury or motor neuron diseases in humans.