( Purkinje cell, PC) PC. Acta Physiologica Sinica Tsinghua Tongfang Optical Disc Co., Ltd. All rights reserved.

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1 , , 51 (2), Acta Physiologica Sinica (, 21009) ( 100 mol/ L) (9414 %, 51/ 54), (516 %, / 54) Ca 2 + / Mg 2 +, ( n = 4) H 2 ranitidine (011 5 mol/ L) ( n = 20), H 1 triprolidine (015 5 mol/ L) ( n = 9) ( n = 4), H 2, 2 : ; ; 2 ; : Q426, [1, ], [1,2,, 2 ], H 1 H 2 [1, ], [4, ] ( Purkinje cell, PC) PC, 2 15 SD ( g) (No , ) (No195215) (No1BK97045) : Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Japan

2 (artificial cerebrospinal fluid, ACSF), m 0 min ACSF [ ( 012), ph714, 2 ml/ min ], 95 % O 2 5 % CO 2 ACSF (mmol/ L) : NaCl 124, KCl 5, MgSO 4 11, KH 2 PO 4 112, NaHCO 26, CaCl 2 214, glucose 10 Ca 2 + / Mg 2 + ACSF,, Ca mmol/ L, Mg mmol/ L [4 ] ( 2 mol/ L NaCl, 2 M ) PC, ( RBI, 100 mol/ L, 1 min), PC, H 1 triprolidine ( Sigma, mol/ L) H 2 ranitidine (RBI, mol/ L) PC, 15 min ACSF PC, ( bin 1 s), t 1 PC ranitidine triprolidine PC Fig. 1 Excitatory responses of a PC to histamine and antagonistic effects of ranitidine and tripro2 lidine on the histamine2induced excitatory responses A1 Excitatory responses of the PC to histamine in normal ACSF. B and C1 Responses of the PC to histamine when the slice was equilibrated with ACSF containing ranitidine and triprolidine respectively. D1 Dose2response curve showing the effects of histamine on the discharge rate of PC perfused with normal ACSF and the ACSF containing histamine receptor antagonists. The horizontal bars and numerals above each histogram indicate the 1 min period and the concentration ( mol/ L) of histamine application respectively.

3 2 : PC PC, Hz, 56 PC ( 100 mol/ L), 54 (9614 %, 54/ 56) 54, 51 (9414 %, 51/ 54) ( 1A), (516 %, / 54) ( 2) 4 PC Ca 2 + / Mg 2 + ACSF, 4 ACSF ( ) 2 PC Fig. 2 Inhibitory responses of a PC to histamine PC Ca 2 + / Mg 2 + ACSF Fig. The excitatory responses of a PC to histamine in normal and low Ca 2 + / high Mg 2 + ACSF The arrow indicates the moment when normal ACSF was replaced by low Ca 2 + / high Mg 2 + medium. 21 H 1 H 2 PC H 1 triprolidine H 2 ranitidine PC, ranitidine (011 5 mol/ L) PC ( n = 20) ; triprolidine (015 5 mol/ L) ( n = 4) ( n = 9) PC 1A D, PC 5,10 0 mol/ L (A D) ; ranitidine (012 mol/ L), ( P < 0105, B D) ; triprolidine (2 mol/ L),, (C D) [4 ], PC, 2

4 222 51, PC, Ca 2 + / Mg 2 +, Ca 2 + / Mg 2 + ACSF PC, PC, PC(516 %, / 54) ( 1 2),, Ca 2 + / Mg 2 + ACSF, PC, ranitidine PC, triprolidine PC, PC H 2 H 1 H 2,, H 2 [5,6 ], H 2 Ca 2 + K + [7,8 ] CA1 H 2 [9 ], H 2 PC, 2 (multi2layered fibers) [2, ],, ( 52HT ) [10 ], PC PC,, [2 ], 2 [11 ], 2 2 [1 ] Schwartz JC, Arrang JM, Garbrag M, et al. Histaminergic transmission in the mammalian brain. Physiol Rev, 1991, 71 : [2 ] Dietrichs E, Haines DE, Rose GK, et al. Hypothalamocerebellar and cerebellohypothalamic projections : circuits for regulating nonsomatic cerebellar activity? Histol Histoph, 1994, 9 : [ ] Vizuete ML, Traiffort E, Bouthenet ML. Detailed mapping of the histamine H 2 receptor and its gene transcript in guinea2pig brain. Neuroscience, 1997, 80 : [4 ] Tang XH, Wang JJ, Li WC, et al. Effects of histamine on the electrical activity of rat cerebellar cortical granule cells. Chin Sci Bull ( ), 1996, 41 : [5 ] Wang JJ, Dutia MB. Effects of histamine and betahistine on rat medial vestibular nucleus neurones : possible mechanism of action of anti2histaminergic drugs in vertigo and motion sickness. Exp Brain Res, 1995, 105 : [6 ] Jones H, Bradley PB, Roberts F. Histamine2induced excitation of spontaneously active medullary neurones in the rat brain is mediated by H 2 2receptors. Neuropharmacology, 1985, 24 : [ 7 ] Phelan KD, Nakamura J, Gallagher JP. Histamine depolarises rat medial vestibular nucleus neurons recorded in2

5 2 : 22 tracellularly in vitro. Neurosci Lett, 1990, 109 : [8 ] Serafin M, Khateb A, Vibert N, et al. Medial vestibular nucleus in the guinea2pig : histaminergic receptors : I. An in vitro study. Exp Brain Res, 199, 9 : [9 ] Haas HL, Greene RW. Effects of histamine on hippocampal pyramidal cells of the rat in vitro. Exp Brain Res, 1986, 62 : [10 ] Gardette R, Crepel F. Differential modulation by serotonin of the responses induced by excitatory amino acid in cerebellar nuclei neurons and Purkinje cell. In : Trouillas P, Fuxe K, eds. Serotonin, the Cerebellum and Ataxi2 a. New York : Raven Press, 199, [11 ] Pu YM, Wang JJ, Wang T, et al. Cerebellar interpositus nucleus modulates neuronal activity of lateral hypoth2 alamic area. NeuroReport, 1995, 6 : Acta Physiologica Sinica Apr. 1999, 51 (2), THE EXCITATORY EFFECTS OF HISTAMINE ON CEREBELLAR CORTICAL PURKINJE CELLS IN THE RAT This work was supported by grants from the National Natural Science Foundation of China (No , ), a grant from the Natural Science Foundation of Jiangsu Province (No1BK97045), and a grant for scholars returning from overseas from the Education Ministry of China (No195215). Corresponding author TIAN L E, WEN YUN2QING, LI HONG2ZHAO, XIONG HUA2BAO, WANG J IAN2JUN ( Department of Biological Science and Technology, Nanjing University, Nanjing 21009; Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Japan) ABSTRACT The effects of histamine on Purkinje cells ( PCs) in lobule of cerebellar cortex were investigated in rat cerebellar slices. Histamine elicited PCs responses predominately excitatory (9414 %, 51/ 54), only few inhibitory (516 %, / 54). The excitatory re2 sponse could not be abolished by perfusing the slices with low Ca 2 + / high Mg 2 + medium. The excitatory response of PCs to histamine could be blocked by histamine H 2 receptor an2 tagonist ranitidine, but not by H 1 receptor antagonist triprolidine readily. These results suggest that histamine exerts an excitatory effect on the PCs via H 2 receptors. Presum2 ably, hypothalamo2cerebellar histaminergic fibers participate in the regulation of somatic and non2somatic functions of the cerebellum. Key words : histamine ; cerebellar Purkinje cell ; hypothalamo2cerebellar histaminergic fibers ; cerebel2 lar slice