Behavioral Evaluation Of BK Knockout Mice And Interaction Between BK Channel And TRPV1 Channel In Mouse Hippocampus Neuron

Objectives: To evaluate behavioral differences between BK channel knockout(KO)and wildtype(WT) mice. To study whether BK channel and TRPV1 channel form functionally coupled complex in mouse hippocampus neuron.Methods : The body size and weight, locomotion activity of BK KO and BK WT mice were measured; Tail suspension test(TST), forced swimming test(FST), acoustic startle resonse repulse inhibition(PPI) test and rota-rod test(RRT) were used to evaluate behavioral properties of BK KO and BK WT mice. Fluorescence immunocytochemistry was used to explore the cellular localization of BK channel and TRPV1 channel; Coimmunoprecipitation was used to test whether BK channel and TRPV1 channel form complex in mouse hippocampus neuron; Whole cell patch clamp was used to record the functional coupling between BK channel and TRPV1 channel in primary mouse hippocampus neuron.Results : The BK KO mice possess smaller size and lower body weight; they show increased locomotion time, shorter immobility time in TST and FST, higher PPI value and shorter duration remaining on the rotor in RRT comparing with BK WT mice.Fluorescence and coimmunoprecipitation experiments showed that BK and TRPV1 were able to form a TRPV1-BK complex. Patch-clamp recording showed that BK channels could be activated by a Ca2+ influx through TRPV1 channels in mouse hippocampus neuron.Conclusion:Compare to BK WT mice, BK KO mice are lighter and resistant to anxiety, depression and schizophrenia; and they develop motor impairment. BK channel and TRPV1 channel form functionally coupled complex in mouse hippocampus neuron.