Selective effects of serotonin upon excitatory amino acid-induced depolarizations of Purkinje cells in cerebellar slices from young rats

1989 ◽  
Vol 492 (1-2) ◽  
pp. 371-376 ◽  
Author(s):  
T.P. Hicks ◽  
M. Krupa ◽  
F. Cre´pel
Keyword(s):  
Amino Acid ◽  
Purkinje Cells ◽  
Excitatory Amino Acid ◽  
Young Rats ◽  
Selective Effects

Slow excitatory amino acid receptor-mediated synaptic transmission in turtle cerebellar Purkinje cells

1990 ◽  
Vol 63 (3) ◽  
pp. 637-650 ◽  
Author(s):  
L. J. Larson-Prior ◽  
D. R. McCrimmon ◽  
N. T. Slater
Keyword(s):  
Amino Acid ◽  
Purkinje Cells ◽  
Excitatory Amino Acid ◽  
Motor Pattern ◽  
Pattern Generation ◽  
Resting Membrane Potential ◽  
Excitatory Amino Acid Receptor ◽  
Acid Receptor ◽  
Synaptic Potentials ◽  
Cerebellar Purkinje Cells

1. The excitatory synaptic responses of turtle Purkinje cells to climbing and parallel fiber (CF and PF) stimulation have been studied by the use of intrasomatic and intradendritic recordings in intact cerebellum and brain stem-cerebellum preparations in vitro. 2. Activation of CF inputs from the cerebellar peduncle or the region of the inferior olive evoked complex spikes followed by slow excitatory postsynaptic potentials (EPSPs), both of which were evoked in an all-or-none fashion. 3. Single stimuli applied to the cerebellar molecular layer activated fast PF-mediated EPSPs; brief trains of PF stimuli (2-5 stimuli, 50-100 Hz) evoked volleys of fast EPSPs followed by a slow, long-lasting EPSP. The amplitude of the fast and slow PF-mediated EPSPs were both graded with stimulus intensity. 4. Slow EPSPs evoked both by CF and PF stimulation were associated with an increase in membrane conductance and were increased in amplitude by hyperpolarization. 5. The CF-evoked slow EPSP was profoundly attenuated by repetitive activation at interstimulus intervals of less than 15-20 s, whereas the PF-evoked slow EPSP was not reduced by repetitive activation. 6. The PF-evoked slow EPSP readily triggered dendritic pacemaker discharges when activated at or near resting membrane potential. The activation of this potential by phasic PF volleys may, therefore, provide an appropriate synaptic drive to cerebellar Purkinje cells to entrain the intrinsic pacemaker properties of these cells to cycles of motor activity. 7. Both slow synaptic potentials were blocked by the excitatory amino acid antagonists kynurenate and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), but not by DL-2-amino-5-phosphonovalerate (DL-AP5) or L-serine-O-phosphate (L-SOP). The PF-evoked slow EPSP was selectively antagonized by L-2-amino-4-phosphonobutyrate (L-AP4; 20-100 microM). 8. It is suggested that the CF- and PF-evoked slow EPSPs observed in this study represent a novel class of excitatory amino acid receptor-mediated slow synaptic potentials activated by Purkinje cell afferents, which may play a role in synaptic integration and motor pattern generation in the cerebellum.

scholarly journals Is visceral sympathoexcitation to heat stress dependent on activation of ionotropic excitatory amino acid receptors in the rostral ventrolateral medulla?

2011 ◽  
Vol 301 (2) ◽  
pp. R548-R557 ◽  
Author(s):  
M. J. Kenney ◽  
C. N. Meyer ◽  
K. G. Hosking ◽  
R. J. Fels
Keyword(s):  
Heat Stress ◽  
Amino Acid ◽  
Excitatory Amino Acid ◽  
Rostral Ventrolateral Medulla ◽  
Ventrolateral Medulla ◽  
Inhibitory Input ◽  
Excitatory Amino Acid Receptors ◽  
Amino Acid Receptors ◽  
Young Rats ◽  
Stress Dependent

Acute heat stress activates visceral sympathetic nerve discharge (SND) in young rats, and the functional integrity of the rostral ventrolateral medulla (RVLM) is required for sustaining visceral sympathoexcitation during peak increases in internal body temperature (Tc). However, RVLM mechanisms mediating SND activation to hyperthermia remain unknown. In the present study, we investigated the role of RVLM ionotropic excitatory amino acid receptors in mediating visceral SND activation to heat stress in anesthetized, young rats. The effects of bilateral RVLM kynurenic acid (Kyn; 2.7 and 5.4 nmol), saline, or muscimol (400–800 pmol) microinjections on renal SND and splenic SND responses to heat stress were determined at peak hyperthermia (Tc 41.5°C), during progressive hyperthermia (Tc 40°C), and at the initiation of heating (Tc increased from 38 to 38.5°C). RVLM Kyn microinjections did not reduce renal and splenic SND recorded during progressive or peak hyperthermia and did not attenuate SND activation at the initiation of heating. In fact, renal and splenic SND tended to be or were significantly increased following RVLM Kyn microinjections at the initiation of heating and during hyperthermia (40 and 41.5°C). RVLM muscimol microinjections at 39, 40, and 41.5°C resulted in immediate reductions in SND. These data indicate that RVLM ionotropic glutamate receptors are required for mediating visceral sympathoexcitation to acute heating and suggest that acute heating activates an RVLM ionotropic excitatory amino acid receptor dependent inhibitory input, which reduces the level of visceral SND to heating.

Serotonin depresses excitatory amino acid-induced excitation of cerebellar Purkinje cells in the adult rat in vivo

1993 ◽  
Vol 608 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Jeffrey G. Netzeband ◽  
Luther B. Weathers ◽  
Howard K. Strahlendorf ◽  
Jean C. Strahlendorf
Keyword(s):  
Amino Acid ◽  
Purkinje Cells ◽  
Excitatory Amino Acid ◽  
Adult Rat ◽  
Cerebellar Purkinje Cells

Synaptic transmission between rat inferior olivary neurons and cerebellar Purkinje cells in culture

1990 ◽  
Vol 63 (1) ◽  
pp. 181-189 ◽  
Author(s):  
T. Hirano
Keyword(s):  
Membrane Potential ◽  
Amino Acid ◽  
Purkinje Cell ◽  
Purkinje Cells ◽  
Excitatory Amino Acid ◽  
Outward Current ◽  
Nmda Antagonist ◽  
Cells In Culture ◽  
Cerebellar Purkinje Cells ◽  
Inferior Olivary

1. Monosynaptic excitatory connections between rat inferior olivary neurons and cerebellar Purkinje cells were studied in culture. Cerebellar cells were dissociated and cultured with small pieces of tissue excised from inferior olivary region. 2. Stimulation of inferior olivary neurons elicited an all-or-none response, which resembled a climbing fiber response, in a whole-cell current-clamped Purkinje cell. Under a voltage-clamp condition of a Purkinje cell, large excitatory postsynaptic current (EPSC) was recorded. 3. The inward EPSC recorded at -50 mV decreased in amplitude as the membrane potential was set more positive and reversed to the outward current around -10 mV. The amplitude of the EPSC changed linearly with the membrane potential between -90 and 10 mV, both in Mg2(+)-free and Mg2(+)-containing solutions. 4. The EPSC was suppressed with excitatory amino acid antagonist kynurenate or gamma-D-glutamylglycine (DGG) at 1 mM. Specific N-methyl-D-aspartate (NMDA) antagonist, DL-2-amino-5-phosphonovalerate (APV), little affected the EPSC at 0.2 mM. 5. The results indicate that the functional synapses were formed between inferior olivary neurons and cerebellar Purkinje cells in culture and suggest that the major postsynaptic receptors at the synapse are excitatory amino acid receptors of non-NMDA type.

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