TY - JOUR
T1 - Cerebellar α 6 -subunit-containing GABA A receptors
T2 - a novel therapeutic target for disrupted prepulse inhibition in neuropsychiatric disorders
AU - Chiou, Lih Chu
AU - Lee, Hsin Jung
AU - Ernst, Margot
AU - Huang, Wei Jan
AU - Chou, Jui Feng
AU - Chen, Hon Lie
AU - Mouri, Akihiro
AU - Chen, Liang Chieh
AU - Treven, Marco
AU - Mamiya, Takayoshi
AU - Fan, Pi Chuan
AU - Knutson, Daniel E.
AU - Witzigmann, Chris
AU - Cook, James
AU - Sieghart, Werner
AU - Nabeshima, Toshitaka
PY - 2018/6
Y1 - 2018/6
N2 - Background and Purpose: The pathophysiological role of α 6 -subunit-containing GABA A receptors, which are mainly expressed in cerebellar granule cells, remains unclear. Recently, we demonstrated that hispidulin, a flavonoid isolated from a local herb that remitted a patient's intractable motor tics, attenuated methamphetamine-induced hyperlocomotion in mice as a positive allosteric modulator (PAM) of cerebellar α 6 GABA A receptors. Here, using hispidulin and a selective α 6 GABA A receptor PAM, the pyrazoloquinolinone Compound 6, we revealed an unprecedented role of cerebellar α 6 GABA A receptors in disrupted prepulse inhibition of the startle response (PPI), which reflects sensorimotor gating deficits manifested in several neuropsychiatric disorders. Experimental Approach: PPI disruptions were induced by methamphetamine and NMDA receptor antagonists in mice. Effects of the tested compounds were measured in Xenopus oocytes expressing recombinant α 6 β 3 γ 2S GABA A receptors. Key Results: Hispidulin given i.p. or by bilateral intracerebellar (i.cb.) injection rescued PPI disruptions induced by methamphetamine, ketamine, MK-801 and phencyclidine. Intracerebellar effects of hispidulin were mimicked by Ro15-4513 and loreclezole (two α 6 GABA A receptor PAMs), but not by diazepam (an α 6 GABA A receptor-inactive benzodiazepine) and were antagonized by furosemide (i.cb.), an α 6 GABA A receptor antagonist. Importantly, Compound 6 (i.p.) also rescued methamphetamine-induced PPI disruption, an effect prevented by furosemide (i.cb.). Both hispidulin and Compound 6 potentiated α 6 β 3 γ 2S GABA A receptor-mediated GABA currents. Conclusions and Implications: Positive allosteric modulation of cerebellar α 6 GABA A receptors rescued disrupted PPI by attenuating granule cell activity. α 6 GABA A receptor-selective PAMs are potential medicines for treating sensorimotor gating deficits in neuropsychiatric disorders. A mechanistic hypothesis is based on evidence for cerebellar contributions to cognitive functioning including sensorimotor gating.
AB - Background and Purpose: The pathophysiological role of α 6 -subunit-containing GABA A receptors, which are mainly expressed in cerebellar granule cells, remains unclear. Recently, we demonstrated that hispidulin, a flavonoid isolated from a local herb that remitted a patient's intractable motor tics, attenuated methamphetamine-induced hyperlocomotion in mice as a positive allosteric modulator (PAM) of cerebellar α 6 GABA A receptors. Here, using hispidulin and a selective α 6 GABA A receptor PAM, the pyrazoloquinolinone Compound 6, we revealed an unprecedented role of cerebellar α 6 GABA A receptors in disrupted prepulse inhibition of the startle response (PPI), which reflects sensorimotor gating deficits manifested in several neuropsychiatric disorders. Experimental Approach: PPI disruptions were induced by methamphetamine and NMDA receptor antagonists in mice. Effects of the tested compounds were measured in Xenopus oocytes expressing recombinant α 6 β 3 γ 2S GABA A receptors. Key Results: Hispidulin given i.p. or by bilateral intracerebellar (i.cb.) injection rescued PPI disruptions induced by methamphetamine, ketamine, MK-801 and phencyclidine. Intracerebellar effects of hispidulin were mimicked by Ro15-4513 and loreclezole (two α 6 GABA A receptor PAMs), but not by diazepam (an α 6 GABA A receptor-inactive benzodiazepine) and were antagonized by furosemide (i.cb.), an α 6 GABA A receptor antagonist. Importantly, Compound 6 (i.p.) also rescued methamphetamine-induced PPI disruption, an effect prevented by furosemide (i.cb.). Both hispidulin and Compound 6 potentiated α 6 β 3 γ 2S GABA A receptor-mediated GABA currents. Conclusions and Implications: Positive allosteric modulation of cerebellar α 6 GABA A receptors rescued disrupted PPI by attenuating granule cell activity. α 6 GABA A receptor-selective PAMs are potential medicines for treating sensorimotor gating deficits in neuropsychiatric disorders. A mechanistic hypothesis is based on evidence for cerebellar contributions to cognitive functioning including sensorimotor gating.
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U2 - 10.1111/bph.14198
DO - 10.1111/bph.14198
M3 - Article
C2 - 29518821
AN - SCOPUS:85044219476
VL - 175
SP - 2414
EP - 2427
JO - British Journal of Pharmacology
JF - British Journal of Pharmacology
SN - 0007-1188
IS - 12
ER -