HCN channels in the hippocampus regulate active coping behavior. Issue 6 (9th August 2018)

• Record Type: Journal Article
• Authors: Fisher, Daniel W.; Han, Ye; Lyman, Kyle A.; Heuermann, Robert J.; Bean, Linda A.; Ybarra, Natividad; Foote, Kendall M.; Dong, Hongxin; Nicholson, Daniel A.; Chetkovich, Dane M.
• Is Part Of: Journal of neurochemistry. Volume 146:Issue 6(2018)
• Page Start: 753
• Page End: 766
• Publication Date: 2018-08-09
• Subjects: coping -- HCN Channel -- hippocampus -- mice -- TRIP8b; Neurochemistry -- Periodicals; 616.8042
• DOI: 10.1111/jnc.14539
• Languages: English
• ISSNs: 0022-3042

Abstract

Abstract : Abstract: Active coping is an adaptive stress response that improves outcomes in medical and neuropsychiatric diseases. To date, most research into coping style has focused on neurotransmitter activity and little is known about the intrinsic excitability of neurons in the associated brain regions that facilitate coping. Previous studies have shown that HCN channels regulate neuronal excitability in pyramidal cells and that HCN channel current (Ih ) in the CA1 area increases with chronic mild stress. Reduction of Ih in the CA1 area leads to antidepressant‐like behavior, and this region has been implicated in the regulation of coping style. We hypothesized that the antidepressant‐like behavior achieved with CA1 knockdown of Ih is accompanied by increases in active coping. In this report, we found that global loss of TRIP8b, a necessary subunit for proper HCN channel localization in pyramidal cells, led to active coping behavior in numerous assays specific to coping style. We next employed a viral strategy using a dominant negative TRIP8b isoform to alter coping behavior by reducing HCN channel expression. This approach led to a robust reduction in Ih in CA1 pyramidal neurons and an increase in active coping. Together, these results establish that changes in HCN channel function in CA1 influences coping style. Abstract : Active coping is an adaptive stress response that improves the outcomes in medical and neuropsychiatric diseases. To date, most research into coping style has focused on neurotransmitter activity and little is known about the intrinsic excitability of neurons in the associated brain regions that facilitate coping. Previous studies have shown that HCN channels regulate neuronal excitability in pyramidal cells and that HCN channel current (Ih) in the dorsal hippocampal (dHC) CA1 increases with chronic mild stress. In this report, we found that global loss of TRIP8b, a necessary subunit for proper HCN channel localization in pyramidal cells, led to active coping behavior in numerous assays specific to coping style. Using a viral strategy in CA1 to knockdown Ih via a dominant negative TRIP8b isoform, we achieved an increase in active coping through greatly reduced Ih in these CA1 pyramidal cells. Together, these results establish that changes in HCN channel function in CA1 influences coping style.